Activin receptor type-2A (ACVR2A) is also known as Activin receptor type IIA, ACTR-IIA, ACTRIIA and ACVR2,which is single-pass type I membrane protein. ACVR2A belongs to the protein kinase superfamily,TKL Ser/Thr protein kinase family and TGFB receptor subfamily.On ligand binding,ACVR2A can forms a receptor complex consisting of two type II and two type I transmembrane serine/threonine kinases. Type II receptors phosphorylate and activate type I receptors which autophosphorylate, then bind and activate SMAD transcriptional regulators.ACVR2A is Receptor for activin A, activin B and inhibin A as well. Several type I I activin receptors have been identified and bind to different activins with different affinities.