Bone formation and bone resorption rates in femur from Darc-KO mice. Bone formation is calculated as bone formation surface (BF) divided by total bone surface (BS). Bone resorption (Trap%) is calculated as (the resorbing surface/bone surface) × 100. The data are expressed as the percentage of wild-type values, n = 8–13, (*) P < 0.05 vs. wild-type control mice.