ATM and osteoporosis: Analysis of the mouse bone mass and density, bone formation and resorption rates, and proliferation and differentiation of osteoblasts and osteoclasts established three mouse models for bone-related diseases: Atm-/- mice as a model for post-menopausal osteoporosis, c-Abl-/- as a model for senile osteoporosis and p53-/- mice as model for osteosclerosis.