ERCC2 and colorectal cancer: After carefully reviewing, 40 eligible case-control studies (3 studies not consistent with HWE were also shown) on the relationship between XPD Lys715Gln polymorphism and digestive cancers risk were involved in this meta-analysis, including 4 oral cancer studies [62]–[65], 13 esophageal cancer studies [27]–[39], 12 gastric cancer studies [36], [40]–[50] and 11 colorectal cancer studies [51]–[61].