KDR and medullary thyroid gland carcinoma: Other signaling pathways that have been implicated in the growth and invasiveness of MTC are the epidermal growth factor receptor (EGFR), the vascular endothelial growth factor receptor (VEGFR) and the hepatocyte growth factor receptor (c-MET) pathways.21–23 Therefore, targeting these receptors has also been of interest as a way of inhibiting or blocking these aberrant signaling pathways.