For example, multiple clinical trials with imatinib that blocks kinase activity of PDGFR and c-kit, have given rise to severe complications that are commonly associated with tumor hemorrhage in young patients with neuroblastoma, GBM and gastrointestinal stromal tumors [54–57] (see following Sections 4.1 & 4.2). The gene discussed is PDGFRB; the disease is glioblastoma.