The limited number of proteomic studies performed in the field of mastocytosis individuated pro-inflammatory factors as novel potential blood biomarkers for systemic mastocytosis (SM) [26] and proinflammatory mechanisms possibly involved in pathogenesis of mastocytosis, as the upregulation of the signaling pathways downstream of Toll-like receptor 4, TNF-a, and IFN-g [27]. Here, TLR4 is linked to mastocytosis.