CTLA4 and colorectal carcinoma: Although PD−1/PD−L1 or CTLA−4 blockade significantly prolongs overall survival in patients with PD−L1–positive advanced non–small cell lung cancer (NSCLC), unresectable stage III–IV melanoma, and CRC—with the greatest benefit observed in dMMR/MSI−H CRC—these therapies can also induce immune−related adverse events (irAEs) in a subset of patients, potentially limiting their broader applicability (29–32).