It is shown that the presence of the APOE ε4 allele, altered miRNA expression and epigenetic dysregulationin the promoter region and exon 1 of TREM2, aswell as ANK1 hypermethylation and altered levelsof histone post-translational methylation leading to increased transcription ofTNFA, could variously explain increased levelsof peripheral and central inflammation found in AD. This evidence concerns the gene ANK1 and Alzheimer disease.