PER2 and type 2 diabetes mellitus: Although similar rhythmicity was visible in cells of trained lean (TL) and type 2 diabetic patients (T2D), differences in time did not reach statistical significance for PER2 (p = 0.13 and p = 0.12 in TL and T2D respectively) whereas one-way ANOVA revealed significant differences for all four donor groups for PER3.