Several immune checkpoints have been described and constitute promising therapeutic targets for cancer immunotherapy, including CTLA-4 (cytotoxic T lymphocyte antigen-4) [14], PD-1 (programmed death-1) [15], LAG-3 (lymphocyte activation gene-3) [16], TIM-3 (T-cell immunoglobulin and mucin domain-3) [17], BTLA (B and T lymphocyte attenuator) [18], TIGIT (T-cell immunoreceptor with immunoglobulin and ITIM domain) [19], and VISTA (V-domain Ig suppressor of T-cell activation) [20]. The gene discussed is LAG3; the disease is cancer.