The cortical area with the highest tangle count and tau burden in hippocampal sparing AD was not found to differ for percentage of CD68 burden (median [IQR], 0.46% [0.32%-0.75%]) compared with either typical AD (median [IQR], 0.75% [0.51%-0.98%]; post hoc P = .06) or limbic predominant AD (median [IQR], 0.40% [0.32%-0.57%]; post hoc P = .37). This evidence concerns the gene MAPT and Alzheimer disease.