Notably, the combination of Cd with other environmental elements (arsenic and lead) robustly increased APP, BACE-1, and PSEN1 which led to Aβ aggregation, supposing a synergistic effect of Cd with other environmental factors which trigger AD pathologies (Ashok et al., 2015; Zhou et al., 2015). This evidence concerns the gene BACE1 and Alzheimer disease.