Increased Rankl expression in the bone marrow of aged mice. Bone marrow was flushed out from 3-month- and 2-year-old mice, RNAs were extracted, and quantitative RT-PCR was performed. The expression of Rankl and adipogenic marker genes, adiponectin (Adipoq), adipocyte P2 (Ap2), and PPARγ (Pparg), was examined and normalized by Gapdh. n = 3 mice; *, p < 0.05. The RT-PCR shown is representative of two independent experiments all displaying similar results.