ATAD2 and cancer: ATAD2: ATPase family AAA‐domain containing protein 2 (ATAD2 or ANCCA) is a bromodomain (BD) containing protein which acts as an epigenetic regulator and transcriptional cofactor for oncogenic transcription factors, such as ERα, AR, E2F, and Myc.[116, 117, 118] ATAD2 interacts with histone acetylation marks on newly synthesized histone H4.[119] Its overexpression is associated with different cancer types, however, its validation as a drug target is very challenging due to the lack of isoform‐selective and cell active ATAD2 inhibitors.