UM is molecularly distinct from cutaneous melanoma (CM)—the two diseases are characterized by completely different driver mutations, B-Raf proto-oncogene (BRAF), NRAS proto-oncogene (NRAS), and neurofibromin 1 (NF1) [4] in CM and G-protein subunit alpha Q (GNAQ) [5], G-protein subunit alpha 11 (GNA11) [6], cysteinyl leukotriene receptor 2 (CYSLTR2), phospholipase C beta 4 (PLCB4) [7], BRCA1-associated protein 1 (BAP1) [5,6,8], splicing factor 3B1 (SF3B1) [9], serine and arginine rich splicing factor 2 (SRSF2) [10], and eukaryotic translation initiation factor 1A X-linked (EIF1AX) [11] in UM. The gene discussed is PLCB4; the disease is cutaneous mastocytosis.