A clinical study conducted in AD patients with mild cognitive deficits concluded that both doxycycline and rifampicin efficaciously reduce the cognitive decline in treated patients (Loeb et al., 2004), possibly and partly via a mechanism involving ABCB1, as both molecules have been reported to induce ABCB1 expression (Wolf et al., 2012). This evidence concerns the gene ABCB1 and Cognitive impairment.