1.7 III (b) VEGF: VEGF is also known as vascular permeability factor (VPF) is an endothelial cell specific mitogen in in vitro and is the main factor responsible for vasculogenesis and angiogenesis in a variety of in vivo models. The gene transcripts level of VEGF is stimulated at the time of implantation because process of implantation occurs under hypoxic condition. In rodents, VEGF is involved during embryo–endometrium crosstalk by regulating endothelial cell proliferation and vascular permeability of endothelial cells at implantation sites in rodents (Rabbani and Rogers, 2001; Rockwell et al., 2002). The VEGF’s mRNA and protein expression level has been noticed in endometrial stomal, endothelial, and glandular cells during the mid-secretory stage in the human (Charnock-Jones et al., 1993).…