The activation of immune checkpoint molecules like programmed death-1 (PD-1), T cell immunoglobulin and mucin domain-containing-3 (TIM-3), cytotoxic T-lymphocyte associated protein-4 (CTLA-4) [112], lymphocyte-activation gene 3 (LAG-3) [113], B7 homolog 3 protein (B7-H3) [114], T-cell immunoreceptor with Ig and ITIM domains (TIGIT) [115], serve as negative regulators of anti-tumor immune response. The gene discussed is CTLA4; the disease is neoplasm.