STAT3 and neoplasm: The expression of STAT3 mRNA in tumor tissue in the control group was significantly increased, while it was reduced in the CM group (although the difference was not statistically significant; P > 0.05) and significantly reduced in the PD-L1 inhibitor and CM + PD-L1 inhibitor groups (compared to the control group; P < 0.05) (Figure 4B).