Although we failed to detect a clear correlation between CCNE1 level and malignancies in both established ovarian cancer cell lines as well as primary tumor specimens (Figures 1 and 2), the frequent CCNE1 gene amplification in ovarian cancer and the ability of CCNE1 to facilitate the formation of HGSOC from FTSECs indicates that ovarian cancer cells with elevated CCNE1 expression could have developed addiction to CCNE1 overexpression for cell growth/survival. Here, CCNE1 is linked to ovarian cancer.