Effects of canonical Wnt signaling on osteogenesis by hMSCs in an ectopic bone formation model. (A–F) hMSC-vector cells alone (A), hMSC-Wnt1 cells alone (B), or hMSC-vector cells mixed with hMSC-Wnt1 cells (C–F) at ratio of 1:1 (C), 3:1 (D), 10:1 (E), or 20:1 (F). b, bone; HA, HA/TCP. Arrows designate osteocytes within bone structures in eosin-stained sections. (G) Quantitative analysis of bone formation by hMSCs in the recovered implants of A–F. Results represent mean values ± SD from experiments performed in triplicate. Bars, 100 µm.