Preclinical studies have also demonstrated intersection between the VEGFR and EGFR pathways in tumor cells, and shown that the activating ligand for vascular endothelial growth factor receptor (VEGFR), VEGF, is sometimes overexpressed in resistant EGFR-mutated lung adenocarcinoma, providing autocrine signaling [90,91]. Here, EGFR is linked to lung adenocarcinoma.