MMP2 and melanoma: It has been recently demonstrated that active MMP-2 regulates vascular endothelial growth factor A (VEGF-A) expression in melanoma cells on a transcriptional level via an αvβ5 integrin/phosphoinositide-3-kinase–(PI3K) dependent pathway [20], which results in activation of the endothelium, an essential step for the adhesion of circulating tumor cells.