STAT3 and gastric cancer: Surprisingly, MG132 blocked the effect of CPX on the expression of total STAT3 and p-STAT3 (Ser727), but not p-STAT3 (Tyr705), which suggested that p-STAT3 (Ser727) levels may be dependent on STAT3 protein level, while other mechanisms may be responsible for CPX-reduced reduction in p-STAT3 (Tyr705) levels in GC cells (Fig. S5a).