Western blot analyses of Sarkosyl-soluble and -insoluble fractions of the frozen normal control and AD brain samples (Brodmann area 6 [BA6], Supplementary Table 3B) revealed that the expression of plexin-B3 was detected only in the Sarkosyl-soluble fractions (Fig. 6m). Here, PLXNB3 is linked to Alzheimer disease.