ARID1A and ovarian clear cell cancer: By far, the most commonly mutated BAF subunit in cancer is ARID1A (BAF250A), the AT-rich interacting domain-containing protein 1A, which is mutated in 50% of ovarian clear-cell carcinoma (OCCC), 11% of colorectal adenocarcinoma3,39–43 and 9% of endometrial carcinoma44, 17.5% of colon and rectal cancers45, certain pancreatic cancer46, 13% of transitional cell carcinoma of the bladder47, 27% of gastric cancer41,48, 16.7% of cholangiocarcinoma49, and 11% of childhood neuroblastoma50.