PER2 and diabetes mellitus: In line with this, the protein-coding gene with the strongest downregulation was Aryl Hydrocarbon Receptor Nuclear Translocator Like (Arntl, Bmal, Bhlhe5), which is a circadian master regulator repressed by Per2. Arntl is associated with susceptibility to hypertension and diabetes and can activate the TNF receptor Osteoprotegerin [22–24].