Stromal cell-derived factor 1/CXCR4 signaling is critical for the recruitment of mesenchymal stem cells to the fracture site during skeletal repair in a mouse model - Kitaori, T; Ito, H; Schwarz, E M; Tsutsumi, R; Yoshitomi, H; Oishi, S; Nakano, M; Fujii, N; Nagasawa, T; Nakamura, T (Arthritis Rheum, 2009)