We measured resorufin fluorescence generated with and without HRP, PMSF and catalase (Fig. 4a and b) from four cell lines: AML12 mouse hepatocytes; MRC5, a primary human fibroblast strain; C2C12 undifferentiated mouse myoblasts; and Hep G2 human hepatocellular carcinoma cells. The gene discussed is CAT; the disease is hepatocellular carcinoma.