Pierson WE, Peters PN, Chang MT, et al. - Researchers conducted whole-exome sequencing to develop an unbiased genetic profile of molecular alterations in endometrioid ovarian tumors with an object to better understand this disease in the context of epithelial ovarian cancer and endometrioid uterine cancers. Whole-exome sequencing was conducted on endometrioid ovarian carcinoma (EOVC) samples (n = 26) and matched normals (n = 15). At similar frequencies in UCEC, significantly mutated genes were found in EOVC (PTEN, CTNNB1, PIK3CA, KMT2D, KMT2B, PIK3R1, ARID1A, and TP53). The authors discovered that EOVC are a molecularly heterogeneous group of epithelial ovarian cancers with distinct mutational signatures. In an age of precision oncology, to facilitate genomically driven oncologic treatments, there is a pressing need to consider the unique molecular drivers in uncommon histologic subtypes.