p16 INK4a is one of the inhibitors of cyclin dependent kinase(cdk),which inhibits cdk4/cdk6 mediated phosphorylation of retinoblastoma gene product (Rb) that leads to cell cycle arrest in G 1 phase.

• p16 INK4a是一种细胞周期蛋白依赖激酶 (cdk)的抑制因子 ；它通过抑制cdk4与cdk6的活性 ；使视网膜母细胞瘤抑制蛋白Rb处于低磷酸化状态 ；从而使细胞阻滞于G1期 .