XPA and hepatocellular carcinoma: In the screening stage, six SNPs of five genes in three steps of NER pathways were associated with HCC risk, including three risk SNPs (XPA rs10817938, XPC rs1870134 and ERCC2 rs238417) and three protective SNPs (ERCC1 rs2298881 and rs3212961, and ERCC5 rs873601).