Activin B is a TGF beta family member that exhibits a wide range of biological activities including regulation of embryogenesis, osteogenesis, hematopoiesis, reproductive physiology and hormone secretion from the hypothalamic, pituitary and gonadal glands. Activin B, like certain other members of the TGF beta family, signals through the ActRII receptor (Activin Receptor type II). Alternative Names: Inhibin beta-2 protein, Activin beta-B protein