CDKN2A and cataract: Cell cycle inhibitor p16 is an important marker of senescent cells and genetic ablation of p16 from aged/senescent cells in old or progeroid mouse models can improve cataracts, sarcopenia, cardiomyocyte, cancer development, renal glomerulosclerosis, osteoarthritis, atherosclerosis, hypertrophy, tumorigenesis, adipose atrophy, and tau-based disorder [6,10,14,15,16,78], thus increasing animal lifespan [15,16].