p21 gene

Patent Granted p21 / WAF1 / CIP1 also known as cyclin-dependent kinase inhibitor 1 or CDK-interacting protein 1 is a protein that in humans is encoded by the CDKN1A gene located on chromosome 6 (6p21.2). p21 is a potent cyclin-dependent kinase inhibitor (CKI). The p21 (CIP1/WAF1) protein binds to and inhibits the activity of cyclin-CDK2, -CDK1, and -CDK4/6 complexes, and thus functions as a regulator of cell cycle progression at G1 and S phase.[5] In addition to growth arrest, p21 can mediate cellular senescence. One of the ways it was discovered was as a senescent cell-derived inhibitor.