Osteoporosis is a very common disease in aging societies, leading to a decrease in bone mass and strength and ultimately fragility fractures. Fragility fractures cause pain and an immobilization and lead to an increased morbidity and mortality. Thus, osteoporosis has a great socio-economic impact that is very likely to increase as populations age. Bones are constantly dismantled and rebuild by bone-resorbing osteoclasts and bone-forming osteoblasts. Thus, current specific osteoporosis therapies are focusing on decreasing bone resorption or on increasing bone formation. However, the drugs that are available thus far have side effects, might not be applicable due to concomitant diseases or can only be administered for a limited period of time. It is therefore important to better understand the molecular and cellular processes by which the bone tissue is formed and resorbed, to identify novel targets that could facilitate the development of future therapies. This project is focusing on exploring novel regulatory circuits of the Wnt pathway, which is known to be a strong inducer of bone formation.