NRAS and Miyoshi myopathy: MM is genetically distinct from cutaneous melanoma (CM)4 with higher incidences in KIT5 6 and NRAS mutations7 but a lower rate of BRAF V600 alterations.8 In general, MM harbors a much lower tumor mutational burden (TMB) than CM, as DNA mutations caused by chronic ultraviolet sun exposure are not a major disease mechanism for MM.9 Such distinctions at the molecular level may lead to different responses to standard treatment between these two melanoma subtypes.