Our results indicated that while decreases in CAT, GPx, and NQO1 activities in BCC patients and in protein expressions of CAT, GCLC, GPx, Nrf2, and MnSOD in BCC tissues compared to epidermis of control subjects were observed, plasma SOD activities and GSH levels were higher in BCC patients than in control subjects. Here, CAT is linked to skin basal cell carcinoma.