PIDD1 and Cognitive impairment: Brain anatomical evidence for the human PIDD1 mutations comes from both PIDD1 families for which MRI brain images were available, and Pidd1−/− mouse brain anatomical analysis has not been performed yet, but it is also clear that, as with CRADD/cradd, the ablation of mouse Pidd1 does not appear to cause the degree of cognitive deficit seen in humans with disruption of the C-terminal PIDD1 DD and PIDD-CC function.