Activin RIB, also known as activin receptor type-1B (ACVR1B) or ALK-4, is a type I transmembrane serine/threonine kinase receptor that is part of the TGF-beta receptor superfamily. Activin binds to a type II activin receptor (ACVR2or ACVR2B) and then recruits ACVR1B[1][2][3]. Activin RIB/ALK-4 Protein, Mouse (HEK293, Fc) is produced in HEK293 cells with a C-Terminal Fc-tag. It consists of 95 amino acids (L32-E126).
