PDCD1 and hepatocellular carcinoma: (iii) It has been observed that DCs, and monocytes and B cells from HCC tumors, express the respective ligands for the inhibitory receptors programmed cell death protein 1 (PD-1), T cell immunoglobulin and mucin-domain containing-3 (TIM3), lymphocyte-activation gene 3 (LAG3) and CTLA-4, for which CD4+ and CD8+ T cells were significantly enriched in HCC patients.