We carried out a novel clinical biomarker investigation of the blood of systemic mastocytosis patients versus healthy controls; utilizing a new and emerging technology platform Sequential Window Acquisition of all Theoretical fragment-ion spectra mass spectrometry (SWATH-MS). This is the first use of this novel proteomic technique in the study of mastocytosis. A Swath-MS based biomarkers dsicovery study for systemic mastocytosis with orthogonal validation of biomarkers via ELISA.