KIT and myelodysplastic syndrome: For example, in patients with a known mast cell disease, elevated tryptase, or an identified KIT mutation, mast cells have to be examined in order to exclude or confirm the presence of a concomitant systemic mastocytosis (SM‐MDS) (Valent, Akin, et al., 2007; Valent, Akin, Hartmann, et al., 2017; Valent, Akin, & Metcalfe, 2017).