So we performed a subgroup analysis according to tumor type, and the results showed that the heterogeneity disappeared obviously in CRC(P for heterogeneity = 0.211, I2 = 36.1%, random-effects model), and other types of cancer(P for heterogeneity = 0.516, I2 = 0.0%, random-effects model), while the heterogeneity still existed in NSCLC(P for heterogeneity = 0.107, I2 = 61.6%, random-effects model) which might be caused by the different cut-off value methods which were adopted to define the high GAS5 expression group or low GAS5 expression group. The gene discussed is GAS5; the disease is colorectal carcinoma.