The MR analysis based on large-scale proteomic data of plasma chemokine levels [59, 60] and a genetic study of AD [3] showed that CCL5 (p = 0.0055, β =  − 0.0667, Table 3) was causally linked to AD without the reverse causal effect (p = 0.7864, β = 0.0078). This evidence concerns the gene CCL5 and Alzheimer disease.