Figure 3. Mechanical loading increase STAT3 expression in bone tissues. STAT3 positive osteoblasts at the periosteal surface of ulna and osteocytes in the cortex (indicated by arrows) were present in the loaded ulna (B) but not in the control ulna (A) by immunohistochemical staining with anti-STAT3 antibody, suggesting the involvement of STAT3 in mechanotransdcution.