Despite this, we did not find any differences in circadian rhythmicity in the core molecular clock components BMAL1, CRY1, PER2 and PER3 between donor groups, which could indicate that the core molecular clock is not affected in muscle of type 2 diabetic patients, as was shown in temporal series of human white adipose tissue biopsies35. Here, PER3 is linked to type 2 diabetes mellitus.