Markers of cellular senescence include functionally activated p53- and p16INK4A (p16)-related tumor suppressor pathways, increased cellular senescence-associated β-galactosidase activity (SA-β-gal), and increased expression of CDK inhibitors, including p15INK4B, p16, and p21CIP1 (p21) [1, 10–12]. The gene discussed is CDKN2A; the disease is neoplasm.