Reptin/RuvBL2 and Pontin/RuvBL1 are closely related members of the AAA+ (ATPase associated with diverse cellular activities) superfamily of proteins, and are putatively homologous to bacterial RuvB proteins that drive branch migration of Holliday junctions. Reptin and Pontin function together as essential components of chromatin remodeling and modification complexes, such as INO80, TIP60, SRCAP, and Uri1, which play key roles in regulating gene transcription. In their capacity as essential transcriptional co-regulators, Reptin and Pontin have both been implicated in oncogenic transformations, including those driven by c-Myc, beta-catenin, and E1A.