KDR and cancer: VEGFA secreted from cancer cells binds to VEGFR2 on endothelial cells, phosphorylates and activates VEGFR2, which then phosphorylates downstream extracellular signal-regulated kinase (ERK1/2) thus promoting angiogenesis (Ferracini et al., 1995; Fischer et al., 2004; Testini et al., 2019).