Interestingly, these genes, such as BHLHE41 [51,52], CRTC2 [53,54], CRY2 [55,56] and TEF [57], are involved in regulating circadian rhythms and various biological processes, including transcription regulation, signal transduction, and metabolic pathways, which are critical in the pathophysiology of T2DM. Here, CRY2 is linked to type 2 diabetes mellitus.