AIF1 and Alzheimer disease: However, the existence of a highly significant correlation between two different microglial markers, P2ry12 and Iba1, in both the DG and CA3 subfields from samples of different Braak pathology (from Braak II to Braak V–VI individuals) strongly suggests that the microglial degeneration in Braak V–VI patients, at these particular hippocampal areas, could be part of a continuum along with the progression of the AD.