p15INK4b

p15INK4b, also known as CDKN2B, is a gene that encodes a protein belonging to the INK4 family of cyclin-dependent kinase inhibitors. These inhibitors play a crucial role in regulating the cell cycle, specifically by preventing the phosphorylation of the retinoblastoma protein (Rb). The INK4 family, which includes p16INK4a, p18INK4c, and p19INK4d, targets specific cyclin-dependent kinases (CDKs), namely CDK4 and CDK6. By inhibiting these CDKs, p15INK4b effectively halts cell cycle progression at the G1 phase, thereby preventing uncontrolled cell division. This mechanism is vital for maintaining cellular homeostasis and preventing the development of cancer. The p15INK4b protein functions by binding to and inactivating CDK4/6 complexes. Loss or mutation of the p15INK4b gene is frequently observed in various cancers, suggesting its role as a tumor suppressor. Its expression is often regulated by factors such as transforming growth factor-beta (TGF-β), which can induce its expression and promote cell cycle arrest. Research into p15INK4b continues to explore its potential as a therapeutic target for cancer treatment, aiming to restore its tumor-suppressive function.