Indeed, clinical studies demonstrate that pruritus may occur in 11–21% of patients treated with anti-PD-1/-L1 inhibitor, 24.4–35.4% of patients treated with CTLA-4 inhibitor, and 33.2–47% of patients in dual CTLA-4/PD-1 blockade (Geisler et al., 2020; Nishijima et al., 2017; Sibaud et al., 2016). This evidence concerns the gene CTLA4 and Pruritus.