CDKN1B（cyclin dependent kinase inhibitor 1B），癌症关联基因，基因ID：1027，该基因编码一种细胞周期蛋白依赖激酶抑制剂，与CDK抑制剂CDKN1A/P21具有有限的相似性。编码蛋白结合并阻止细胞周期蛋白E-CDK2或细胞周期蛋白D-CDK4复合物的激活，从而控制细胞周期在G1的进展。这种蛋白的降解是由其依赖于CDK的磷酸化和随后由scf复合物泛素化引起的，是细胞从静止状态向增殖状态过渡所必需的。该基因突变与多发性内分泌肿瘤IV型（MEN4）有关。This gene encodes a cyclin-dependent kinase inhibitor， which shares a limited similarity with CDK inhibitor CDKN1A/p21. The encoded protein binds to and prevents the activation of cyclin E-CDK2 or cyclin D-CDK4 complexes， and thus controls the cell cycle progression at G1. The degradation of this protein， which is triggered by its CDK dependent phosphorylation and subsequent ubiquitination by SCF complexes， is required for the cellular transition from quiescence to the proliferative state. Mutations in this gene are associated with multiple endocrine neoplasia type IV (MEN4).关联癌症：乳腺癌、头颈部鳞状细胞癌。关联化疗药物：拉帕替尼。