Abstract
Tumor suppressor activity of the retinoblastoma protein pRB is preserved despite loss of interaction with E2F transcription factors (E2F) or proteins harboring a leucine-x-cysteine-x-glutamic acid motif (LxCxE, where x is any amino acid). This indicates that pRB uses several parallel pathways to suppress tumorigenesis, which may also include E2F- and LxCxE-independent interactions.