These humanized monoclonal antibodies target inhibitory receptors (CTLA-4, PD-1, LAG-3, TIM-3) and ligands (PD-L1) expressed on T lymphocytes, antigen-presenting cells, and tumor cells, eliciting an anti-tumor response by stimulating the immune system [97,98,99]. The gene discussed is CTLA4; the disease is neoplasm.