PDCD1 and hepatocellular carcinoma: Since the PD-1/PD-L1 blockade has proven to be an efficient treatment for HCC (Kudo, 2016), the lack of parallel changes in the frequency of PD-1.6 A allele in HCV-related HCC patients and controls in our series excludes a simple direct effect of PD-1.6 variant in the pathogenesis of HCC.