CTLA4 and cutaneous mastocytosis: Furthermore, it is well known that UM and skin cutaneous melanoma (CM) have similar cell sources, and currently, promising immunotherapies, such as ipilimumab (anti-CTLA4), nivolumab (anti-PD1), and durvalumab (anti-PDL1), are being successfully applied for the clinical treatment of CM, with great improvements in patient survival rates [38, 39].