STAT3 and renal cell carcinoma: The results from MTS assay demonstrated that these two inhibitors displayed a synergistical growth suppression effect in both ACHN and 786-O cells (Fig. 4j), and the overexpression of G6PD in ACHN cells, which had the lowest G6PD activity in the three of the RCC cell lines, could rescue this tendency (Fig. 4k), indicating that G6PD overexpression is necessary for NF-κB/STAT3 promoted ccRCC proliferation.