P42771

p16 INK4A is also known as CDKN2A, MLM, ARF is often transcriptionally activated in cells undergoing senescence and is one of the main regulators of this program, and it is upregulated in multiple tissues during aging. p16 INK4A plays a crucial role as a negative regulator of the cell cycle, specifically inhibiting cyclin-dependent kinase 4 (Cdk4) activity, which is essential for the transition from the G1 phase to the S phase of the cell cycle. By binding to Cdk4, p16 INK4A prevents the formation of the active Cdk4/cyclin D complex, thereby halting cell proliferation and maintaining cellular integrity. This regulatory function is particularly important in the context of tumor suppression, as the gene encoding p16 INK4A is frequently altered in various cancers, with homozygous deletions and point mutations observed in established human tumor cell lines.