In this study, we review the current understanding of immune inhibitory receptors such as PD-1, CTLA-4, CD244, Lymphocyte activation gene 3 (LAG-3), T cell immunoglobulin domain and mucin domain-3 (Tim-3), and CD160 (expressed on virus-specific T cells in hepatitis). This evidence concerns the gene PDCD1 and hepatitis A virus infection.