Metastatic bone lesions accompanied with increased expression of Pancytokeratin in the bones of arthritic PyV MT mice. A-F: Representative x-ray images of bones. A-D: Bones from C57/BL6 mice injected with CII at 9 and 18 wks and PyV MT mice with no metastatic lesions; E and F: Bones from PyV MT + CII at 9 wks and 18 wks respectively (shows distinct severe osteolytic bone lesion in distal femur as indicated by the arrow). N = 8 mice from each group were examined using the x-ray imaging. G-I: Pancytokeratin positive staining observed in the bones of arthritic PyV MT mice. Brown staining represents positive staining. The images were taken at 400× magnification. Representative of n = 10 mice is shown.