The retracted paper, “Human epididymis protein 4 in association with Annexin II promotes invasion and metastasis of ovarian cancer cells,” appeared in Molecular Cancer on 1 November 2014 as article 243 in the journal’s thirteenth volume. Its author list—Huiyu Zhuang, Mingzi Tan, Juanjuan Liu, Zhenhua Hu, Dawo Liu, Jian Gao, Liancheng Zhu and corresponding author Bei Lin—came from the Department of Obstetrics and Gynecology at Shengjing Hospital of China Medical University in Shenyang, in China’s northeastern Liaoning Province. The study argued that HE4 does not merely mark the presence of epithelial ovarian cancer in the bloodstream but actively participates in the disease’s progression, associating with Annexin II to boost the capacity of tumor cells to invade surrounding tissue and colonize distant sites. That framing mattered, because a biomarker that drives malignancy is not just a passive signal of disease but a potential therapeutic target, and the paper was read as evidence for exactly that possibility.

HE4, known formally as WFDC2, is a secreted glycoprotein belonging to the whey acidic protein (WAP) four-disulfide core domain family, a group of small proteins defined by a conserved motif locked into shape by four disulfide bonds. First characterized in the epithelium of the distal epididymis, the protein was later found to be strongly overexpressed in epithelial ovarian carcinoma, particularly the serous and endometrioid subtypes, and readily detectable in serum. Immunoassays for HE4 gained regulatory clearance in the late 2000s for monitoring women with epithelial ovarian cancer, and the marker entered everyday practice through composite tools such as the Risk of Ovarian Malignancy Algorithm, which combines HE4 with the older marker CA-125 to help evaluate pelvic masses. The protein’s normal physiological function remains debated, with proposed roles ranging from protease inhibition to antimicrobial defense along the reproductive tract. Precisely because HE4 is easy to measure and tracks closely with tumor burden, laboratories worldwide have asked whether it also acts inside the tumor itself—driving proliferation, adhesion, invasion and treatment resistance—rather than simply mirroring disease from a distance.

Annexin II, more commonly styled Annexin A2 or ANXA2 in the current literature, is a 36-kilodalton member of the annexin family of calcium-dependent phospholipid-binding proteins. It shuttles between the cytoplasm, nucleus and cell surface, where it frequently pairs with the S100A10 protein to form a heterotetrameric complex that organizes membrane trafficking, cytoskeletal remodeling and the assembly of plasmin-generating complexes on the outer face of the plasma membrane. Those functions place ANXA2 squarely within the machinery that cells deploy to migrate, degrade extracellular matrix and invade neighboring tissue—the processes that convert a localized tumor into metastatic disease. A reported physical association between HE4 and ANXA2 therefore offered an attractive, testable explanation for how an abundantly secreted biomarker could translate into invasive behavior. The 2014 paper built its case on experiments in which HE4 expression was manipulated in ovarian cancer cell lines, including Caov-3 cells, with figures presenting western blots, invasion readouts and time-lapse-style migration panels that appeared to show sharp differences between control and HE4-expressing cells.

Trouble surfaced long after publication. According to the retraction note, concerns were raised about highly similar images within the article and between it and another publication from shared authors. That second paper, published in Oncotarget in 2016 by Zhu and colleagues—several of whom also appeared on the retracted study—reported that overexpression of HE4 enhances the proliferation, invasion and metastasis of ovarian cancer. The retraction notice itemizes the correspondences: Figure 3D panels from the Molecular Cancer paper showing ANXA2 and HE4 immunoblot results in mock-transfected Caov-3 cells appear highly similar to Figure 1D panels in the Oncotarget paper showing HE4-labeled and mock-transfected Caov-3 samples. In plain terms, images that were supposed to document distinct experiments—different constructs, different conditions, in two different journals—look, to the editors, like the same underlying pictures recycled with new labels, a form of duplication that undermines the independence of both datasets.

The internal duplications are equally consequential. The notice states that in Figure 4D of the retracted paper, lane 1 at the zero-hour time point appears highly similar to lane 7 at the same time point, and that in Figure 4E, panel 1 at zero hours appears highly similar to panel 3. Figure 4F, which contains Caov-3 panels, shows pairs—1 and 4, 1 and 5, and again 1 and 4—that partially overlap. The zero-hour notation is the signature of wound-healing or transwell-style migration assays, in which researchers photograph the starting state of the assay and then track how quickly cells close a scratch or traverse a membrane over subsequent hours. Each condition in such an experiment begins with its own scratch in its own monolayer, so even the baseline photographs of different samples are expected to differ in texture, cell density and scratch geometry. When supposedly independent starting images turn out to be nearly identical, or two images partially overlap, the comparisons built on top of them lose their evidentiary footing: the apparent gap between treated and untreated cells, or between HE4-overexpressing and control cells, may be an artifact of reused photographs rather than genuine biology.

Under the publication-ethics guidelines that govern journals such as Molecular Cancer, editors are obliged to give authors the opportunity to respond to such concerns, whether by producing original, unmanipulated data or by explaining the similarities. The retraction note records that the authors were given that opportunity and did not respond to the editors’ correspondence about the retraction. The publisher could not contact Liancheng Zhu or Juanjuan Liu at all, while all other authors, including corresponding author Bei Lin, did not respond to the publisher regarding the retraction. Faced with that silence and with what the notice describes as a significant number of errors, the Editor-in-Chief concluded that confidence in the presented data could no longer be maintained, and the article was formally retracted more than a decade after it first appeared. The retraction note itself, published as Volume 25, article 207 of the journal, is open access and is now linked to the original paper in the journal’s record.

The case illustrates how modern research-integrity scrutiny operates. Image forensics—checks for duplicated panels, pixel-level overlay comparisons, contrast and brightness analyses, and screening tools that flag reused western blots across thousands of manuscripts—has become routine for large publishers, and readers increasingly report suspicious figures directly to journals. Editors can act years or even decades after publication because the images remain part of the permanent scholarly record, and retraction, far from erasing a paper, formally warns every future reader that its conclusions cannot be trusted. In this instance, the cross-paper duplication was especially damaging: overlapping figures in two venues from a shared author group suggested a pattern spanning manuscripts and journals rather than a one-off production error. The retraction notice identifies the 2016 Oncotarget paper by its own DOI, but the formal action concerns the 2014 Molecular Cancer article, whose record now carries the retraction through the journal’s Crossmark article-versioning service, ensuring that readers who land on the original page will see the notice attached.

For clinicians and researchers, the retraction draws a bright line between two distinct strands of HE4 science. The protein’s standing as a serum biomarker rests on large, independent clinical studies and regulatory evaluations that do not depend on the retracted mechanistic work, and the retraction does not touch that literature. What is withdrawn is the specific claim, as presented in the 2014 paper, that HE4’s association with Annexin II promotes invasion and metastasis of ovarian cancer cells. Research groups will now have to weigh how much of the mechanistic edifice they constructed around that finding needs re-examination, and authors who cited the paper—many of whom did so to support HE4’s proposed pro-invasive role—will need to update their reference lists. Retractions of this kind also serve a quieter function: they signal to early-career scientists that image reuse is detectable, that it tends to surface eventually, and that silence in the face of editorial queries usually ends in retraction rather than clarification.

The retraction note is deliberately spare: seven flagged image pairs, two unreachable authors, a decision that the data can no longer be trusted, and no author rebuttal on the record. A paper published at the height of the biomarker-discovery era, from a hospital department deeply engaged in ovarian cancer research, fell to a pattern of duplicated images that survived peer review, production and years of citation. The episode is a reminder that in modern science publication is not the end of scrutiny but the beginning of it, and that the credibility of a biomarker’s mechanistic story depends on the integrity of every panel in every figure. For readers who encounter HE4 in the clinic or the laboratory, the protein itself remains a legitimate object of study; the cautionary tale now sits, permanently attached, in the bibliographic record of Molecular Cancer.

In this landmark study, the researchers employed cutting-edge mass spectrometry techniques to perform a comprehensive proteomic analysis of ovarian carcinoma samples. By systematically analyzing protein expression levels across a broad spectrum of tumor types and stages, they aimed to identify distinctive proteomic signatures that could be leveraged for clinical applications. This effort represents a substantial leap forward in our understanding of how molecular variations correspond to differing clinical outcomes in ovarian cancer patients.

Emerging evidence suggests that ovarian carcinoma is not a singular entity but rather a collective term encompassing multiple histological subtypes, each with its unique biological behaviors and clinical trajectories. The study astutely categorizes these subtypes and delves into their proteomic profiles, shedding light on potential biomarkers that could assist in tailoring individualized treatment plans. Identifying stage-specific biomarkers is essential as it could provide insights into tumor behavior, response to therapy, and potential outcomes, thereby enhancing the precision of patient management.

The importance of early diagnosis in ovarian cancer cannot be overstated, as early-stage detection significantly correlates with improved survival rates. The study underscores the critical need for novel diagnostic biomarkers that can facilitate earlier and more accurate detection of the disease. By integrating proteomic data with clinical parameters, the researchers hope to establish a robust pipeline for the development of new diagnostic tools capable of detecting ovarian carcinoma at its nascent stages.

As the researchers sifted through their extensive data, they identified a plethora of proteins exhibiting differential expression patterns associated with various histotypes of ovarian carcinoma. Notable among these were proteins implicated in key biological processes such as cell proliferation, apoptosis, and immune response. The study’s findings raise intriguing questions about the functional roles these proteins may play in tumorigenesis and progression, positioning them as promising targets for therapeutic intervention.

One noteworthy aspect of the research is its focus on the tumor microenvironment, which has emerged as a critical player in cancer progression. The study highlights the role of inflammatory mediators and extracellular matrix components that were found to be significantly altered in the cancerous tissues. Understanding how these elements interact with tumor cells can provide valuable insights into potential therapeutic strategies aimed at disrupting the supportive infrastructure that facilitates tumor growth.

As the field of proteomics continues to evolve, so too does the potential for identifying more refined biomarker panels that could translate into clinical utility. The study suggests that integrating proteomic data with genomic and transcriptomic information may lead to a multi-omics approach, one that can offer a holistic view of the tumor’s biology. This integrated strategy may pave the way for creating comprehensive biomarker profiles that can guide patient management decisions more effectively.

While the findings of this study are promising, researchers acknowledged the need for validation in larger, independent cohorts. Translating these proteomic discoveries into routine clinical practice remains a challenge, as the validation process requires extensive collaboration across various institutions and disciplines. Nevertheless, the potential impact on patient care could be profound if successful, providing clinicians with tools to make more informed decisions in diagnosing and treating ovarian cancer.

Furthermore, the study opens up exciting new avenues for future research. Questions remain regarding how identified biomarkers can influence the choice of therapeutics or predict responses to specific treatments, particularly in the context of targeted therapies and immunotherapies that are reshaping the landscape of cancer treatment. Future investigations could elucidate the functional implications of these biomarkers, possibly leading to the identification of novel therapeutic targets.

It is worth noting that the application of proteomic analysis extends beyond ovarian carcinoma alone. Similar methodologies can be adapted for other cancer types, which could ultimately contribute to a broader understanding of cancer biology. By expanding the proteomic framework to encompass a variety of malignancies, researchers could foster cross-disciplinary collaborations that may enhance our collective capability to overcome cancer’s myriad challenges.

The implications of this research are significant, as they not only shed light on the biology of ovarian carcinoma but also provide a foundational basis for subsequent inquiries aimed at enhancing early detection and treatment outcomes. The prospect of developing tailored therapies based on individual proteomic profiles reflects a promising direction for personalized medicine.

In conclusion, the innovative work led by Werner et al. represents a crucial step in the quest for more effective diagnostic and prognostic tools in ovarian carcinoma. Through their meticulous proteomic analysis, they have illuminated the path forward for researchers seeking to understand and combat this formidable disease. With ongoing advancements in technology and a collaborative spirit, the future of ovarian cancer research and treatment holds tremendous promise.

Subject of Research: Ovarian carcinoma proteomic analysis

Article Title: Proteomic analysis of ovarian carcinoma reveals diagnostic and prognostic biomarkers with histotype- and stage-specificity.

Article References:

Werner, L., Ittner, E., Swenson, H. et al. Proteomic analysis of ovarian carcinoma reveals diagnostic and prognostic biomarkers with histotype- and stage-specificity.
J Ovarian Res (2026). https://doi.org/10.1186/s13048-026-01984-4

Image Credits: AI Generated

DOI: 10.1186/s13048-026-01984-4

Keywords: ovarian carcinoma, proteomic analysis, biomarkers, personalized medicine, cancer detection, tumor microenvironment, histotypes, therapeutic targets, personalized treatment.