Images demonstrating clear metastatic lesions in the lungs of arthritic PyV MT mice. A-F: Representative images of lungs showing metastatic lesions. A-C:C57/BL6 mice, C57/BL6+CII at 9 and 18 wks (no metastatic lesions) D: PyV MT mice(no metastatic lesions); E and F: PyV MT+ CII at 9 and 18 wks respectively (arrows represent lung lesions); G-L: H&E of the lung sections: The arrows represent metastatic lesions in PyV MT + CII at 9 and 18 wks (K and L) versus no lesions in control C57/BL6, C57/BL6 + CII at 9 or 18 wks and PyV MT lung (G - J). N = 10-13 mice from each group were examined with similar results. The images of the H&E sections were taken at 400× magnification.