In addition, real‐time polymerase chain reaction (PCR) indicated higher PDCD1 expression in HCC tissue samples carrying a PD‐1.3 G/A allele and a PD‐1.7 G/A or G/G allele than in those with A/A genotypes, respectively, but not in PBMCs of the same patients (Figure 3). The gene discussed is PDCD1; the disease is hepatocellular carcinoma.