In human cancer cells exposed to oxidative stress (H2O2), tyrosine kinases c-abl (abelson murine leukemia viral oncogene homolog 1) and c-abl-related gene (Arg) were able to phosphorylate human CAT enzyme at residues Tyr231 and Tyr386 to inhibit the CAT at the enzyme activity level. This evidence concerns the gene CAT and cancer.