CTLA4 and cancer: Interestingly, these phenotypes broadly correlate with the higher incidence of dose‐dependent toxicities associated with CTLA‐4 inhibition (38.6% and 57.9% of metastatic melanoma patients receiving higher doses of ipilimumab experienced high‐grade toxicities73), in comparison with PD‐1/ PD‐L1 blockade reported to cause high‐grade adverse events from 10% to 15% of patients, over a range of doses,74 indicating the improved tolerance of PD‐1/PD‐L1 inhibitors in cancer patients.