PDCD1 and hepatocellular carcinoma: Two SNP on the chromosome 2 within the PDCD1 gene, the rs36084323 G/A (PD-1.1) located -606 base pairs upstream the promoter region at position 242801596 and the rs10204525 G/A (PD-1.6) located at +8669 base pairs in the 3′ UTR at the position 241850169, have been found to be significantly associated with the risk to develop HBV-related cirrhosis and HCC among a Chinese Han population (Zhang et al., 2010; Li et al., 2013; Peng et al., 2015).