To investigate the pathogenic role of p38α‐MAPK in microglia and peripheral myeloid cells in AD, we cross‐bred APP‐transgenic (APPtg) mice with p38α‐MAPK‐encoding gene Mapk14 floxed mice, and LysM‐Cre+/− mice expressing Cre specifically in the myeloid cell lineage, to obtain APPtgp38fl/flLysM‐Cre+/− (p38α deficient) and APPtgp38fl/flLysM‐Cre−/− (p38α wild type) of genotypes. Here, APP is linked to Alzheimer disease.