According to the results of a recent meta-analysis conducted on 35 RCTs including more than 16,000 patients, hypothyroidism, hyperthyroidism, and pneumonitis occurred more frequently in individuals using PD1/PD-L1 inhibitors, whereas colitis and hypophysitis were more common in those using CTLA4 inhibitors [109]. This evidence concerns the gene CTLA4 and colitis.