MAPT and Alzheimer disease: However, no significant differences in cis P-tau levels were observed between AD and control brains (0.208 ± 0.1 vs. 0.5 ± 0.09, n = 5, p = 0.068), nor were there significant differences in trans P-tau and tau5 levels (0.05008 ± 0.01 vs. 0.05429 ± 0.002, n = 5, p = 0.722; 0.1003 ± 0.04 vs. 0.2611 ± 0.11, n = 5, p = 0.244) (Figure 1d).