PER1 and Alzheimer disease: The comparison of the expression rhythms between controls and AD patients using the repeated measures 2-way ANOVA revealed significant effect of time (PER1: F = 9.435, P < 0.0001; BMAL1: F = 4.637, P < 0.0003) but not significant difference between the clock gene expression profiles in AD patients and controls (PER1: F = 0.537, P = 0.471; BMAL1: F = 1.655, P = 0.211).