Loss of ARID1A sensitizes breast cancer cells to BET inhibition33, and most ARID1A mutated (ARID1AMUT) ovarian clear cell carcinomas showed relative sensitivity to BETi compared with ARID1A wild type (ARID1AWT) in vitro and inhibited tumor growth in vivo as monotherapy34. This evidence concerns the gene ARID1A and neoplasm.