Immunogen sequence: EKPKVNPKLY MCVCEGLSCG NEDHCEGQQC FSSLSINDGF HVYQKGCFQV YEQGKMTCKT PPSPGQAVEC CQGDWCNRNI TAQLPTKGKS FPGTQNFHLE. Activin A receptor, type I (ACVR1) belongs to the transforming growth factor-beta (TGF-beta) superfamily of structurally re