CDKN2D (Cyclin-Dependent Kinase Inhibitor 2D): CDKN2D, also known as p19^INK4d, is one of the INK4 family of cyclin-dependent kinase inhibitors that plays a critical role in regulating cell cycle progression. By inhibiting CDK4 and CDK6, CDKN2D prevents the phosphorylation of the retinoblastoma protein, leading to cell cycle arrest in the G1 phase. Its function as a tumor suppressor highlights its importance in preventing uncontrolled cell proliferation, and loss of CDKN2D function has been implicated in the development of various cancers....