KDR and acute lymphoblastic leukemia: Although BCR-ABL, an abnormal tyrosine kinase that is reported as the hallmark of CML and Ph+ ALL [32, 33], has been identified as the primary target for ponatinib, other targets including platelet-derived growth factor receptor α (PDGFRα), vascular endothelial growth factor receptor 2 (VEGFR2) and fibroblast growth factor receptor 1 (FGFR1) have also been identified to be inhibited by ponatinib [29].