The study has shown downregulation of transcript levels of circadian locomotor output cycles kaput (CLOCK), brain and muscle aryl hydrocarbon receptor nuclear translocator-like 1 (BMAL1), and neuronal PAS domain protein 2 (NPAS2) in PBMCs, as well as significantly decreased CLOCK protein expression in women with PCOS [164]. This evidence concerns the gene CLOCK and polycystic ovary syndrome.