Human Transforming growth factor beta receptor I (TGFβR1), also known as activin A receptor type II-like kinase, AAT5 and LDS1, GenBank Accession No. NM_004612.4, a.a 34-126, fused at the C-terminus of the Fc portion of human IgG1, with C-terminal Avi-tag, expressed in a HEK293 cell expression system and enzymatically biotinylated using Avi-tag™ technology. Biotinylation is confirmed to be ≥90%. MW=39 kDa. This protein runs at a higher molecular weight due to glycosylation.