WNT4 and endometriosis: Structural variations (polymorphisms) or functional insufficiency of the HOXA10 and WNT4 genes and of the genes of their genetic cascade (MIF, VEGFA, MMPs, VCAM, BMP, etc.)may deregulate highly balanced genetic and epigenetic mechanisms of female reproductive tract embryogenesis, causing disorganization of the endometrium as well as dissemination of mesoderm cells, including SCs, outside the uterine cavity; this initiates an inborn predisposition to endometriosis in postnatal life.