Hedgehog signalling

- What is hedgehog signalling? (Describe every detail starting from types of ligands, receptor(s), how it’s activated, how it’s inactivated, downstream processes until gene expression) - How it can induce osteogenesis in mesenchymal stem cells? - what are the gene markers? Transcriiption factors? Proteins markers? - any agonists? Antagonists? Bone diseases associated? Same points should be explained for the following signalling pathways: