Necdin (NDN)

Growth suppressor that eases the entry of the cell into cell cycle arrest. Functionally similar to the retinoblastoma protein it binds to and represses the activity of cell-cycle- boosting proteins such as SV40 large T antigen, adenovirus E1A, and the transcription factor E2F.

Necdin also interacts with p53 and works in an additive manner to inhibit cell growth. Functions also as transcription factor and binds directly to specific guanosine-rich DNA sequences (By similarity).