[Tumor suppressor gene p53].

Alterations of p53 tumor suppressor gene are the most common genetic change detected in human cancers. Several biological functions of p53 have been described, including the induction of G1 arrest and apoptosis following DNA damage or other cellular insults. Biochemical activity of p53 has been proposed as a transcriptional regulator; p53 gene product can bind DNA in a sequence-specific manner and regulate transcription from promoters containing a consensus binding site. It is likely that many of the biological functions of p53 are a result of transcriptional regulation of downstream genes which involve in these functions.