FIG. 1.

Tumor differentiation. (a) Extent of tumor differentiation (papillary and follicular combined), expressed as % of tumor area, showing the similarity between the two exposed groups (exposed, control [Ec], and exposed, selected [Es]), and the unexposed group from the same geographical area (U1), and the considerable increase in the % of differentiation in tumors of group U3 from Japan (U3 vs. Ec; p < 0.0001). (b) Type of differentiation, expressed as % of differentiated tumor (papillary and follicular patterns combined); papillary differentiation is shown. There is a close similarity between the exposed and unexposed groups from the same area, but a considerable increase in the % of the papillary component in the tumors of group U3 from Japan (U3 vs. Ec; p < 0.0001). In both (a) and (b), the England and Wales findings were intermediate between the Chernobyl and the Japanese cases. The whiskers are lines that extend from the box to the highest and lowest values, excluding outliers. A line across the box indicates the median. Circles represent outliers (cases between 1.5 and 3 box lengths from the upper or lower end of the box). Stars represent extremes (cases that are beyond 3 box lengths from the upper or lower end of the box).