In the anti–CTLA-4 monotherapy group, cholecystitis developed in eight patients (1.6%), a significantly higher rate than that seen for anti–PD-1/L1 regimens, in which 15 patients (0.4%) in the monotherapy group and two patients (0.9%) in the combination therapy group developed cholecystitis (P = 0.006; Fig. 1). This evidence concerns the gene CTLA4 and Cholecystitis.