Some studies showed a clear relationship between XPD Lys751Gln polymorphism and an increased risk of leukemia (Juan et al., 2005; Ganster et al., 2009; Shi et al., 2011; Banescu et al., 2014, 2016), while others showed a decreased risk of leukemia (Ozcan et al., 2011; Douzi et al., 2015), and others suggested no association between this polymorphism and leukemia (Seedhouse et al., 2002; Allan et al., 2004; Matullo et al., 2006; Mehta et al., 2006; Pakakasama et al., 2007; Batar et al., 2009; Canalle et al., 2011; Ozdemir et al., 2012; Sorour et al., 2013; Dincer et al., 2015). The gene discussed is ERCC2; the disease is leukemia.