ARID1A and endometrial cancer: Mutations of these 12 genes (STAG2, TAF1, ARID1A, KMT2C, KMT2D, APC, KMT2A, JAK2, BRCA2, PRKDC, ATRX, and BCORL1) were detected in 66% of the endometrial cancer samples (Figures 2A,B).