Consistently, we found that CPX decreased the levels of p-STAT3 (Tyr705), p-Src (Tyr416), and the cell cycle-related proteins CDK4 and Cyclin D1 without any effect on total STAT3 and Src levels in GC cells pretreated with MG132, indicating that CPX may decrease p-STAT3 (Tyr705) level via inhibiting p-Src (Tyr416) (Fig. 4A). This evidence concerns the gene CDK4 and gastric cancer.