Faxitron radiography (Faxitron X-ray Corporation, Wheeling, Illinois, United States) (Figure 3A) and micro–computed tomography (CT) (Figure 3B) revealed significant cortical thinning (arrow) and a reduction in metaphyseal bone (asterisk) in the distal femora of 12-month-old Sam68+/+ mice compared with 4-month-old mice of either genotype and 12-month-old Sam68−/− mice.