Immunogen sequence: NFDNGDSRLD SSEFLKFVEQ NETAINITTY PDQENNKLLR GLCVDALIEL SDENADWKLS FQEFLKCLNP SFNPPE. Follistatin-like protein 1 (FSTL1) is a widely-expressed, extracellular glycoprotein that is homologously grouped into the osteonectin (BM-40/SPARC)