In aortic root atheromas combined over weeks on AD, 13% (3 of 23) of young, 31% (5 of 16) of middle-aged, and 30% (9 of 30) of old ApoE−/− mice contained a necrotic core and the size of this necrotic core tended to be larger in old compared with middle-aged mice (Fig. 3c, P = 0.041). This evidence concerns the gene APOE and Alzheimer disease.