Since the antioxidant response seems to be crucial in the resistance against CLytA-DAAO-induced cell death, in the current work, a pilot study has been initiated to evaluate the CAT, NFE2L2 and GPX2 expression in biopsies from patients with pancreatic carcinoma, colorectal carcinoma, and glioblastoma (Figure 10). The gene discussed is CAT; the disease is glioblastoma.