SOX9 and cancer: Although both ID8 and STOSE cancer cells originated from the OSE, and both resulting tumor types expressed markers of HGSC such as WT1, overall they displayed distinct transcriptional profiles (Fig. 1B; Supplementary Table S4; Supplementary Fig. S1A); for example, Amhr2, Star, and Sox9 were preferentially expressed in ID8-WT and Ccl2, Il33, and Col1a3 were expressed in STOSE (Supplementary Fig. S1B).