Then the secretory products such as TNF-α, IL-8, and VEGF secreted by activated macrophages have the ability to influence each phase of the angiogenic process, including modifying the local extracellular matrix, induction of endothelial cells to migrate or proliferate, and inhibition of vascular growth with formation of differentiated capillaries 147, thus facilitating the proliferation of endometrial cells and subsequently progressing to severe endometriosis. This evidence concerns the gene VEGFA and endometriosis.