HCFC1 and neoplasm: BAP1 tumor suppressor functions have been attributed to its ability to regulate gene transcription via (i) interaction to host cell factor-1 (HCF1), Ying Yang 1 (YY1), and E2F1 [13, 14], (ii) modulation of histone H2A ubiquitylation [15], (iii) maintaining DNA integrity [11, 16] and modulating DNA repair by homologous recombination [12, 16].