XRCC1 and thyroid cancer: Ryu et al. [18] in 2011, Santos et al. [16], Sigurdson et al. [25], García-Quispes et al. [19], Fard-Esfahani et al. [17], Chiang et al. [23] and Akulevich et al. [20] reported that the XRCC1 Arg399Gln polymorphism was not associated with the risk of thyroid cancer.