The incidence of vitiligo, as estimated by the fixed-effect model, was highest for the IO combination (10.1%) and PD-1 monotherapy (7.9%), followed by the IO + chemotherapy (3.7%), CTLA-4 monotherapy (3.2%), and PD-L1 monotherapy (0.54%) groups (p < 0.001) (Figure 4). This evidence concerns the gene CTLA4 and vitiligo.