ARID1A and endometrial cancer: Similarly, ARID1A induces p21 expression in multiple other cell lines, including an ovarian surface epithelial cell line (OSE4), a colorectal cancer cell line (HCT116), a mammary epithelial cell line (MCF10A), and an endometrial cancer cell line (HEC-1A) [13] In these cell lines, ARID1A interreacts with p53 to directly suppress p21 expression at the promoter level [13].