Having met the major criterion (multifocal clusters of MC in at least one organ) and all three minor criteria (KIT point mutation at codon 816, aberrant expression of CD2 and CD25 in MC and baseline serum tryptase level > 20 ng/mL), the diagnosis of systemic mastocytosis (SM) according to WHO 2016 classification was established. Here, CD2 is linked to systemic mastocytosis.