During this process, T cells may up-regulate inhibitory receptors such as Programmed death-ligand 1 (PD-1), Lymphocyte activation gene 3 protein (LAG-3), Cytotoxic T-lymphocyte associated protein 4 (CTLA-4), and T cell immunoglobulin- and mucin-domain-containing 3 (TIM-3), dampening T cell response against infections and tumor cells (7). The gene discussed is CTLA4; the disease is infection.