Whereas heterozygous variants in TREM2 are associated with AD [2, 3, 8], homozygous variants in TREM2 or its binding partner DAP12/TYROBP cause polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL), also known as Nasu-Hakola disease (NHD). This evidence concerns the gene TREM2 and Alzheimer disease.