A neutralizing antibody to IL-6 was found to significantly reduce G6PD expression and STAT3 phosphorylation in prostate cancer cells treated with HS5 CM, demonstrating that bone marrow stromal cell–derived IL-6 can drive up-regulation of G6PD in prostate cancer cells (Fig. 3, K to M). The gene discussed is STAT3; the disease is prostate carcinoma.