Activin A

Activin A is a member of the TGFβ family first identified in late 1980s as an inducer of follicle-stimulating hormone. Similarly to other members of the family, Activin A is highly conserved in evolution and throughout the animal kingdom and regulates a variety of biologic processes including cell proliferation, hematopoiesis, wound healing, and fibrosis. Activin A signals through the activin type I (Alk2, 4, or 7) and type II (ActRII or ActRIIB) receptors and shares with TGFβ the activation of the Smad cascade. Activin A has attracted the attention of immunologists for the ability to modulate innate and adaptive immune responses.