CTLA4 and cancer: With the advent of the era of precision medicine, targeting programmed cell death protein 1/programmed cell death ligand-1 (PD-1/PD-L1) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) has revolutionized cancer treatment and improved the long-term survival rate of patients with advanced NSCLC (7–10).