該基因與腫瘤抑制基因CDKN2A相鄰，位于一個在多種腫瘤中經常突變和缺失的區域。該基因編碼一種與CDK4或CDK6形成復合物的細胞周期蛋白依賴激酶抑制劑，并阻止CDK激酶的激活，因此編碼蛋白作為控制細胞周期G1進展的細胞生長調節劑發揮作用。該基因的表達被發現是由TGF-β顯著誘導的，提示其在TGF-β誘導的生長抑制中的作用。該基因的兩個選擇性剪接轉錄變體編碼不同的蛋白質，已被報道。
This gene lies adjacent to the tumor suppressor gene CDKN2A in a region that is frequently mutated and deleted in a wide variety of tumors. This gene encodes a cyclin-dependent kinase inhibitor, which forms a complex with CDK4 or CDK6, and prevents the activation of the CDK kinases, thus the encoded protein functions as a cell growth regulator that controls cell cycle G1 progression. The expression of this gene was found to be dramatically induced by TGF beta, which suggested its role in the TGF beta induced growth inhibition. Two alternatively spliced transcript variants of this gene, which encode distinct proteins, have been reported.