Here, the authors show that TGFβ1 release from bone matrix during ageing induces degradation of TRAF3 in mesenchymal progenitor cells, leading to reduced osteoblast differentiation and increased osteoclast formation, and suggesting that pharmacological stabilization of TRAF3 could ameliorate age-related osteoporosis. This evidence concerns the gene TGFB1 and osteoporosis.