The retinoblastoma protein (RE) binds to a variety of cellular protein
s and suppresses cellular growth. Such interactions are regulated by p
hosphorylation during the cell cycle by several cyclin-dependent kinas
es, known as RE kinases. Clues to the specific physiological roles of
different RE kinases have been obtained. Moreover, interesting functio
ns of the RE protein, other than control of E2F activity have been fou
nd.