Schwede M, Waldron L, Mok SC, et al. - Given that the focus of recent attempts for improving results for high-grade serous ovarian cancer has been the recognition of molecular subtypes and prognostic gene signatures, but existing subtypes show poor cross-study robustness, so, researchers examined the contribution of cell admixture in published ovarian cancer molecular subtypes and prognostic gene signatures. They found a strong link between recently reported ovarian cancer molecular subtypes and the cell admixture. The division of tumors as distinct molecular subtypes in simulations where the percentage of stromal cells increased was reported. A link of stromal gene expression in bulk tumors with overall survival was identified, and one dataset revealed a link between increased stroma and anatomic sampling location. Based on the findings, experts concluded an influence of cell admixture on the interpretation as well as the reproduction of ovarian cancer molecular subtypes and gene signatures derived from bulk tissue. It is crucial to explain the role of stroma in the tumor microenvironment as well as in prognosis.