Compared to the analysis carried out in all participants, we observed similar direction and magnitude of interaction between SNPs in the UGT1A6 genes, only aspirin use and CRC risk age restricted analysis (Pinteraction = 0.009, I2 = 0 for rs2070959; Pinteraction = 0.01, I2 = 0 for rs1105879; S13 Table). This evidence concerns the gene UGT1A6 and colorectal carcinoma.