SOD2 and neoplasm: Furthermore, western blotting analysis of the tumor tissues from ACHN and 786-O xenografts indicated that caffeine treatment did not affect the expression of G6PDH and STAT3; however, caffeine treatment led to the downregulation of the expression of NOX4, p47-phox, p-STAT3, and cyclin E, whereas the expression of SOD2 was upregulated (Figure 6M).