MEF2A and Alzheimer disease: Consistent with the macrophage SNP enrichment analysis of genome-wide significant loci, AD heritability was significantly enriched at variants in the DHS motif sets SPI1 (PU.1) (enrichment = 8.93, corrected enrichment P = 0.012), MEF2A (enrichment = 19.22, corrected enrichment P = 0.022), CEBPA (enrichment = 9.72, corrected enrichment P = 3.43 × 10− 3) and EGR1 (enrichment = 14.48, corrected enrichment P = 5.14 × 10− 4).