Although expression of CCR5 ligands is altered in AD patients, numerous studies report that CCR5Δ32 mutation, resulting in the loss of CCR5 functionality, does not protect from AD, as the frequency of this allele does not differ between AD patients and healthy controls (Balistreri et al. 2006; Combarros et al. 2004; Huerta et al. 2004; Wojta et al. 2020). This evidence concerns the gene CCR5 and Alzheimer disease.