CNP and systemic mastocytosis: As upregulation of adhesion molecules, activation and sequestration of platelets, leukocytes, pRBCs and RBCs are important features of SM pathogenesis [2,25,39], the findings of low CNP levels in the SM group could be interpreted as an insufficient counterregulatory CNP upregulation – with its possible protective anti-inflammatory and vasodilatory effects – probably due to endothelial damage as mentioned above.