VEGFA and carcinoma: PDGF-DD/PDGFR-β can irritate the proliferation and metastasis of carcinomas.127,128 PDGF-BB is one of the most studied factors in the PDGF family with potent cancer-driving efficacy through various downstream signaling pathways (such as MAPK/ERK,129 PI3K/AKT,130 and JNK pathway), which regulates the proliferation and migration of PDGF-dependent cells.131,132 Over-expressed PDGF signals not only enhance tissue fibrosis but also excite angiogenesis and drug resistance in tumor progression and anti-VEGF therapy.121,133