Secreted signal that acts globally to regulate anterior/posterior axial patterning during development. May play critical roles in patterning both mesodermal and neural tissues (By similarity). It is required for proper vertebral patterning and orofacial development (PubMed:31215115). Signals through activin receptors type-2, ACVR2A and ACVR2B, and activin receptors type-1, ACVR1B, ACVR1C and TGFBR1 leading to the phosphorylation of SMAD2 and SMAD3 (PubMed:28257634). Homodimer; disulfide-linked (PubMed:26919518 and PubMed:31215115). Interacts directly with ACVR2B (By similarity). Interacts directly with ACVR2A (By similarity). Interacts with ACVR1B, TGFBR1 and ACVR1C in an ACVR2B-dependent manner (By similarity). Interacts with FST isoform 2/FS-288 (PubMed:28257634). In the embryo, strong expression is seen in the palatal epithelia, including the medial edge epithelial and midline epithelial seam of the palatal shelves. Less pronounced expression is also seen throughout the palatal shelf and tongue mesenchyme. Synthesized as large precursor molecule that undergoes proteolytic cleavage by furin-like proteases (PubMed:31215115). This produces an inactive form consisting of the mature C-terminal portion non-covalently bound to its cleaved N-terminal propeptide. Activation of the mature form requires additional cleavage of the propeptide by a tolloid-like metalloproteinase. The disease may be caused by variants affecting the gene represented in this entry. Belongs to the TGF-beta family.