Levels of lactate dehydrogenase (LDH), γ -glutamyl transferase (GGT), alkaline phosphatase (ALP), carcinoembryonic antigen (CEA) and cancer antigen 15-3(CA15-3) in serum, and also catalase (CAT) and superoxide dismutase (SOD) activities in tumor tissue were measured. This evidence concerns the gene CAT and neoplasm.