Some evidence suggests that the effects ofp21 inductionon gene expression in senescent cells may contributeto the pathogenesisof cancer and age-relateddiseases.In particular, p21 expression was found to upregulatemultiple genesthat have not only been associated with senescence but also implicatedinage-related diseases, including Alzheimer'sdisease,atherosclerosis, amyloidosis, arthritis and cancer, thus suggesting thatp21 induction by stress may play a causal role in these diseases [6]. The gene discussed is CDKN1A; the disease is cancer.