Despite the impressive impact of CTLA4 and PD1-PDL1-targeted cancer immunotherapy, LAG3 (also named CD223), serving as a cancer immunotherapy target, is the third IR to be targeted in the clinic due to its negative regulatory role for T cells and its capacity, combined with PD1, to mediate a state of exhaustion (15), consequently attracting considerable interest and scrutiny (12). The gene discussed is PDCD1; the disease is cancer.