CAT and leukemia: We speculate that differences in cell cycle (i.e., lymphocytes are in Go cell cycle and cancer cells are constantly dividing cells), differences in glutathione content and/or differences in gene expression of antioxidant proteins (e.g., catalase, thioredoxin, superoxide dismutase, glutathione peroxidase) may explain resistance and/or vulnerability in lymphocyte and leukemia cells against VK3 and VC exposure.