Among various microbial infections, researchers have proposed Chlamydia pneumoniae (CPn) may be implicated in AD pathology and certain antibiotics were determined to exhibit some degree of effectiveness in treating moderate AD (Loeb et al., 2004); however, the results of human and animal studies in past decades were inconsistent (Maheshwari and Eslick, 2015; Woods et al., 2020). Here, CPN1 is linked to Alzheimer disease.