Several biomarkers have been used for quantitative assessment of cell senescence, including senescence-associated β-galactosidase (SA-β gal) and the cyclin-dependent kinase inhibitors, p16INK4A and p21WAF1, involved in the control of growth arrest by two major tumor suppressor pathways, p16INK4A/pRb and p53/p21WAF1 [20, 21]. The gene discussed is CDKN2A; the disease is neoplasm.