 Once a ligand has bound to a receptor, the amount of homomeric receptor oligomers increase, suggesting that the equilibrium shifts towards the homodimeric form.The low affinity for ligands suggests that BMPR2 may differ from other type II TGF beta receptors in that the ligand may bind the type I receptor first.BMPR2 is expressed on both human and animal granulosa cells, and is a crucial receptor for bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF 9).