SIRT3 and gastric cancer: The present study pooled the survival data of 1563 cancer patients from 7 studies and found that SIRT3 overexpression was not associated with OS in various cancer patients (HR = 1.05, 95% CI = 0.51–2.16, P = 0.89), but the subgroup analyses grouped by cancer types revealed that the overexpression of SIRT3 was associated with better overall survival in hepatocellular carcinoma (HR = 0.56, 95% CI = 0.42–0.74, P<0.0001) and gastric cancer (HR = 0.62, 95% CI = 0.43–0.89, P<0.0001) patients.