By blocking transmembrane receptors of the immune checkpoint apparatus, including cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), programmed cell death protein (PD-1), and its ligand (PD-L1), ICIs unleash the adaptive cellular immune system, enabling it to mount a robust and sustained anti-tumor response [13,14]. The gene discussed is CTLA4; the disease is neoplasm.