130 kDa retinoblastoma associated protein, IB4, p130, PRB2, Rb2, Rbl2, RBR2, Retinoblastoma like 2, Retinoblastoma-related protein 2, RIC128.
Key regulator of entry into cell division. Directly involved in heterochromatin formation by maintaining overall chromatin structure and, in particular, that of constitutive heterochromatin by stabilizing histone methylation.