Endocrine gland-derived vascular endothelial cell growth factor (EG-VEGF; also called prokineticin-1) is a member of the prokineticin family of secreted proteins whose distinguishing structural motif involves 10 cysteines that form five intrachain disulfide bonds, creating a “colipase fold” (1, 2). The mouse EG‑VEGF precursor is 105 amino acids in length and contains a 19 aa signal sequence plus an 86 aa mature segment (3). There are no potential N‑linked glycosylation sites, and the secreted molecule is a monomer that is approximately 10 kDa in size. The mature region in mouse is 93% and 87% aa identical to the mature regions in rat and human, respectively. Mature mouse prokineticin-2 is 57% aa identical to mouse EG‑VEGF/prokineticin-1. Mouse EG‑VEGF is active on bovine endothelial cells (3). Although there is considerable aa identity between mouse and human EG-VEGF, the expression patterns are very much different. This is attributed to pronounced differences in the promoter region of the two genes. While human EG-VEGF is expressed by steroidogenic glands, mouse EG‑VEGF is expressed in hepatocytes and renal tubular epithelial cells. EG-VEGF binds to and activates two closely related G-protein coupled receptors, EG‑VEGF/PK1‑R1 and EG‑VEGF/PK2‑R2 (4, 5). Mouse EG‑VEGF stimulates proliferation and survival of liver sinusoidal endothelial cells, and, in mouse, EG-VEGF acts to induce monocyte migration and stimulate hematopoiesis (3, 6).