XRCC1 and hepatocellular carcinoma: Several previous studies have been approved to evaluate the possible association between the single nucleotide polymorphisms (SNPs) in XRCC1 gene (such as arginine (Arg)194 tryptophan (Trp), Arg280 histidine (His), and Arg399 glutamssine (Gln)) and the risk of HCC [13–20].