CDKN1A and retinal disorder: Upregulation of classical senescence-associated markers including p53, p16INK4a, plasminogen activator inhibitor 1 (Pai1), Cdkn1α (p21(CIP/WAF1)), and promyelocytic leukemia protein (PML) provide further evidence for the presence of senescent retinal cells in retinopathies [149].