To solve this issue, we used eukaryotic model cells with impaired antioxidant systems: the yeast Saccharomyces cerevisiae, human cancer cells and modified HEK293 cells with mutations in the SOD2, and Cat genes that resulted in the suppression of the expression of catalase (Cat) and located in mitochondria manganese superoxide dismutase (MnSOD2), enzymes important for the cellular antioxidant system. Here, CAT is linked to cancer.