In the comparison of the CRC and benign mucosal lesions, subgroup analyses of SFRP2 methylation based on detection methods showed that the MSP subgroup had a larger heterogeneity (I2 = 70.9%) than the non-MSP subgroup (I2 = 30.2%), suggesting that MSP subgroup was a main source of heterogeneity. The gene discussed is SFRP2; the disease is colorectal carcinoma.