RBFOX3 and Alzheimer disease: Here, postmortem brain cerebral cortex tissue sections from AD patients carrying the ApoE4 allele and those from age-matched normal individuals were first costained with the lipid droplet surface protein perilipin 2 (PLIN2) and the microglial marker Iba-1, the neuronal marker NeuN, or the astrocyte marker GFAP.