BMP signaling pathways. BMP-7 transduces signals in target cells by binding to a specific membrane bound receptor BMPR2 and phosphorylates BMPR1, which activates both canonical and non-canonical pathways. In the canonical pathway, activated BMPR2 leads to phosphorylation of Smad-1/5/8 which complexes with Smad-4 and translocate the signal. In the non-canonical pathway, p38 MAPK, JNK, ERK and NFKB were activated via the activation of XIAP, TAK1 and TAB1 whereas PI3K, Akt were activated by both BMPR2 and Smad-1/5/8. Altogether, this influences the different transcription factors and regulates the gene expression. BMP: Bone morphogenetic protein; BMPR: Bone morphogenetic protein receptor; XIAP: X-linked inhibitor of apoptosis protein; TAK1:TGF-beta activated kinase 1; TAB1: TAK1 binding protein; Runx2: Run-related transcription factor 2; MAPK: Mitogen-activated protein kinase; JNK: c-Jun-N terminal Kinase; ERK: Extracellular signal-regulated kinase; PI3K: Phosphotidylinositol 3 kinase; Akt: RAC-alpha serine/threonine-protein kinase; mTOR: mammalian target of rapamycin.