The antitumor effect of oxaliplatin against HT29/MDR tumors was fully restored in doxycycline-treated animals, showing a significant decrease in tumor growth, in line with that of oxaliplatin-treated HT29 tumors (Fig. 6a, b), a decrease in the expression of PERK and MRP1, an increase in intratumor apoptosis (Fig. 6c, d). This evidence concerns the gene ABCC1 and neoplasm.