KDR and neoplasm: Hypoxia represents the leading stimulus of many cancer-related events, such as the upregulation of glucose aerobic metabolism [260,261], the activation of angiogenic growth factors and receptors, such as VEGF and VEGFR [262,263], the activation of epithelial–mesenchymal transition pathways [264,265,266], and the recruitment of pro-tumor immune cells, such as myeloid cells [267], regulatory T cells [268], and tumor-associated macrophages [269].