Betacellulin (BTC), a member of the EGF family, is an 80 amino acid heparin-binding protein. Like other members of the EGF family, it is synthesized as a transmembrane precursor, and the soluble cytokine, containing one EGF structural motif, is released by proteolytic cleavage. Lyophilized from 50 mM acetic acid, 0.05% (v/v) TFA.