SORL1 and Alzheimer disease: Quantification of the hybridization signal for the E38E39 probe showed that the majority of PCs (67.3%) expresses high levels of SORL1-fl transcript (group III), and that none of the four groups were affected by AD (group 0, p = 0.4197; group I, p = 0.4674; group II, p = 0.8955; group III, p = 0.5474) (Fig. 4c).