Similarly, treatments with antibiotics significantly reduced Aβ deposits in the cortex (Figure 6, g and h; t test, p < 0.05) and tended to decrease Aβ in the hippocampus (Figure 6, g and i; t test, p = 0.060) of Il-17a-wildtype APP-transgenic mice, but did not change density of methoxy-XO4-stained Aβ deposits in Il-17a-deficient AD mice (Figure 6, j – l; t test, p > 0.05). This evidence concerns the gene IL17A and Alzheimer disease.