KIT and systemic mastocytosis: According to the WHO 2022 classification [9], the diagnosis of systemic mastocytosis (SM) is based on the integration of laboratory parameters (serum tryptase levels, blood chemistry tests), bone marrow (BM) morphological parameters (BM biopsy, BM blood smear), genetic parameters (presence of KIT mutations, cytogenetic alterations, or other markers of clonality), cytometric/immunohistochemical parameters (aberrant expression of membrane antigens), radiological and clinical parameters.