KIT and systemic mastocytosis: Moreover, EVs containing KIT are increased in the serum of patients with systemic mastocytosis (Kim et al., 2018), a clonal disease of the huMC compartment associated with KIT variants, and in the plasma of patients with CD34+ acute myeloid leukaemia (Boyiadzis & Whiteside, 2017; Hong et al., 2014; Szczepanski et al., 2011).