Senescent cells are especially abundant at sites of age-related pathologies, and a great deal of evidence from mouse models demonstrated a causal role of senescent cells in several age-related diseases, such as sarcopenia, lordokyphosis, cataracts, osteoporosis, aged hematopoietic system, vasomotor dysfunction, atherosclerosis, neurodegeneration, idiopathic lung fibrosis, osteoarthritis, hepatic steatosis, and hair loss [6,7,8,9,10,11,12,13,14], demonstrated by genetic approaches the clearance of p16-expressing senescent cells in mice models [15,16]. The gene discussed is CDKN2A; the disease is osteoarthritis.