MAP2K1 and skin neoplasm: MAP2K1 mutations can function as primary drivers or secondary oncogenic events and have been identified in common and congenital nevi, WNT-activated and BAP1-inactivated melanocytomas, and various types of melanomas.2, 3, 4, 5 However, cutaneous melanocytic tumours driven by MAP2K1 mutations, without additional second hit genomic aberrations, could represent a newly identified subclass of neoplasms with a notable genotypic–phenotypic correlation not yet included in the World Health Organization (WHO) Classification of Skin Tumours.6