KDR and Infertility: Sorcin is important for endometrium development and embryo implantation: it is downregulated in the mid-secretory (receptive) endometrium of women with unexplained infertility with respect to fertile women, and mediates endometrial angiogenesis, endothelial proliferation, migration, and invasion via regulation of the vascular endothelial growth factor (VEGF) pathway involving the vascular endothelial growth factor receptor 2 (VEGFR2), phosphatidylinositol 3-kinase (PI3K), Akt, and nitric oxide synthase (NOS) expression, possibly by regulating calcium homeostasis [76,77].