PDGFRB and systemic mastocytosis: The ELISA investigations were in agreement with the SWATH-MS analysis, significant differences between SM patients and controls were seen for CXCL7 (p = 0.0223), LBP (p = 0.0144), TGFβ1 (p = 0.0031), and PDGFRβ (p = 0.0085) (Fig. 5a).