Many studies have reported the association of XRCC1 polymorphisms at 194, 280, and 399 (Arg194Trp, Arg280His, and Arg399Gln) with thyroid cancer risk [16]–[25], but the results were inconclusive, some original studies thought that these polymorphisms were associated with thyroid cancer risk, but others had different opinions. Here, XRCC1 is linked to thyroid gland carcinoma.