The stem-like subtype was predominant in high grade serous ovarian and basal-like breast cancer supporting common biological connections between these cancers that also share BRCA1 dysfunction [9], [44] and p53 mutation [63].Molecular similarities between basal-like breast cancer and high-grade serous ovarian cancer have been described in other studies, including the recent study by the Cancer Genome Atlas Network [64]. Here, BRCA1 is linked to breast cancer.