RB1 and autosomal dominant polycystic kidney disease: HDAC inhibition targeting Rb/E2F has been reported to decrease cystic epithelial cell proliferation and reduce cyst development by acting as an inhibitor of differentiation 2 (Id2) (52) and sirtuin 1 (53), respectively; however, its influence on histone methylation in ADPKD cystogenesis requires further investigation.