Cyclin Dependent Kinase Inhibitor 2A (CDKN2A)

CDKN2A, is a tumor suppressor protein, which in humans is encoded by the CDKN2A gene.P16 plays an important role in regulating the cell cycle, and mutations in p16 increase the risk of developing a variety of cancers, notably melanoma.

This gene generates several transcript variants which differ in their first exons. At least three alternatively-spliced variants encoding distinct proteins have been reported, two of which encode structurally related isoforms known to function as inhibitors of CDK4 kinase. The remaining transcript includes an alternate first exon located 20 Kb upstream of the remainder of the gene; this transcript contains an alternate open reading frame (ARF) that specifies a protein which is structurally unrelated to the products of the other variants.