Concentrations of PDGF and FGF in serum or in plasma during anti-cancer treatment have not yet been fully investigated although a decline in serum PDGF-AA or PDGF-BB has been demonstrated in various cancer types during chemotherapy and/or radiotherapy [35-37], and when combined with multi-tyrosine kinase inhibitors (VEGFR-2, FGF and PDGF) [38]. Here, KDR is linked to cancer.