IL6 and gastric cancer: Subgroup analysis based on country showed that, in Chinese and Japanese GC patients, the increase in postoperative serum IL-6 levels in LAG group were significantly lower than the postoperative increases found in the OG group (Japanese: SMD = −2.03, 95% CI = −2.74 ~ −1.32, P < 0.001; Chinese: SMD = −4.27, 95% CI = −6.40 ~ −2.14, P < 0.001).