In chronic infections and cancers, T-cells become exhausted (3), where they over-express immune-checkpoint receptors (ICRs), such as Cytotoxic T-Lymphocyte–Associated Antigen 4 (CTLA-4), Programmed Death-1 (PD-1), Lymphocyte Activation Gene-3 (LAG-3), and T-cell immunoreceptor with immunoglobulin and ITIM domain (TIGIT), which bind their ligands and lead to defects in proliferation, cytokine production, and cytotoxicity of T-cells. This evidence concerns the gene LAG3 and cancer.