(bone morphogenetic protein 4 bone morphogenetic protein 4 BMP4 Bone morphogenetic protein 4 BMP4 bone morphogenetic protein 4 Bone morphogenetic protein 4 BMP4 BMP4 Bone morphogenetic protein 4 Bone morphogenetic protein 4 bone morphogenetic protein 4 BMP4 bone morphogenetic protein 4 Bone_morphogenetic_protein_4 Bone morphogenetic protein 4 BMP4 Bone morphogenetic protein 4