KDR and cancer: Its co-targeting with other oncoantigens, such as HER-2, can induce a reduction in the invasive potential of cancer cells, including in trastuzumab-resistant cells [110,111], or those that cooperate in the establishment of the tumor microenvironment, such as vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor beta (PDGFR-β), which are also involved in the progression of several cancers, carcinomas, and sarcomas [112,113,114,115,116].