Some inhibitory receptors, such as PD-1, lymphocyte activation gene 3 (LAG-3), T cell immunoglobulin mucin 3 (TIM-3), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), are highly expressed on exhausted T cells during chronic viral infection and tumor progression (14–16). This evidence concerns the gene HAVCR2 and neoplasm.