CDKN1B and neoplasm: FOXO3a binds to the promoter of apoptosis-inducing genes, such as Bcl-2-like protein 11 (Bim), Fas ligand (FasL), and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), and to the promoter of cell cycle inhibitors, such as Cyclin-dependent kinase inhibitor 1A (p21) and Cyclin-dependent kinase inhibitor 1B (p27) [66], thereby acting as a tumor suppressor.