XRCC1 and head and neck squamous cell carcinoma: Studies have investigated the association between XRCC1 Arg399Gln/XRCC1 Arg194Trp polymorphisms and HNSCC risk (Li et al., 2007; Majumder et al., 2007; Applebaum et al., 2009; Gugatschka et al., 2011; Kostrzewska-Poczekaj et al., 2013; Jin et al., 2014; Raturi et al., 2020).