Bone Morphogenetic Protein-5 (BMP-5) is an extracellular multifunctional signaling cytokine that is also a member of the TGF-β family. BMP-5 can bind with TGF-β receptors and trigger SMAD protein signal transduction. It is involved in many negatively regulated physiological processes, such as the aldosterone biosynthetic process and epithelial to mesenchymal transition. BMP-5 also plays a vital role in cartilage synthesis.