To confirm the above findings in other senescent human cells, we examined fibroblasts isolated from a patient with Werner syndrome, which is an autosomal-recessive disorder characterized by the premature appearance of features of normal aging in young adults.12,13 Fibroblasts from a patient with Werner syndrome showed SA-β-gal staining at passage 8 compared with NHDFs at passage 13 (Fig. 4a) as well as higher levels of the senescence markers, p16INK4a and p21 (Fig. 4b). The gene discussed is CDKN2A; the disease is Werner syndrome.