PDGFRB and vascular malformation: Since c-Kit is inhibited by imatinib, which also inhibits the bcr-abl kinase and platelet derived growth factor receptor beta (PDGFRb) [19], we treated mice with GNAQ Q209L-induced vascular malformations with imatinib and noted that imatinib treatment diminished progressive growth of SWS vascular malformations (Figure 5).