Not that I'm aware of. A general difficulty with interpreting case studies also is the number of unmeasured confounding factors. And when studying humans, what

Not that I'm aware of. A general difficulty with interpreting case studies also is the number of unmeasured confounding factors. And when studying humans, what are we checking - is it simply increased rates of cancer? Or if it is behavioral/mental changes, then the natural differences in personal behaviors across individuals would make it practically impossible to set a control. Maybe once we finally develop a clone army we can know for sure.