MITF has been identified as a lineage survival oncogene amplified in malignant melanoma (Garraway et al., 2005), CTLA-4 expression has been shown to be associated with a more favorable prognosis of patients with CM (Goltz et al., 2018), and CD74 was identified as a useful prognostic marker associated with OS of patients in stage III melanoma (Ekmekcioglu et al., 2016). Here, CTLA4 is linked to cutaneous mastocytosis.