Minor diagnostic criteria include co-expression of CD25/CD2/CD30 by neoplastic MCs, 25% of MCs with a spindle-shaped or atypical morphology, the presence of an activating point mutation at codon 816 of KIT (in ≥ 90% KIT D816V, driver mutation), and a serum total tryptase > 20 ng/mL (ICC: in absence of a myeloid neoplasm; WHO-5: adjusted in case of hereditary alpha-tryptasemia). The gene discussed is KIT; the disease is myeloid neoplasm.