In a second MANCOVA that controlled for apoE ε4 status in addition to age, CDR, and presence of infarcts, there was a main effect of PiB on fornix (F1,40 = 6.09, p = 0.02) and splenium (F1,40 = 5.23, p = 0.03) FA and a main effect of WMH pathology on FA in the corona radiata (F1,40 = 23.87, p<0.001), internal capsule (F1,40 = 25.91, p<0.001), superior longitudinal fasciculus (F1,40 = 13.51, p = 0.001), superior fronto-occipital fasciculus (F1,40 = 7.78, p = 0.008), inferior fronto-occipital fasciculus (F1,40 = 8.02, p = 0.007), and body of the corpus callosum (F1,40 = 6.65, p = 0.01). The gene discussed is APOE; the disease is infarction.