Further, measure of bronchiole lumen to wall ratio by morphometric analysis did not demonstrate significant differences between groups because of the extreme variability of the lesions within different areas of the same lobe in individual cats in Groups A and B. Individual cats in Group A and B had areas of very marked SMA-positive infiltration in interstitium and periarteriolar areas 18 months after the initial infection (Fig. 5a). This evidence concerns the gene SMN1 and infection.