CLOCK and hyperinsulinism: For example, homozygous Clock mutant mice (ClockΔ19/Δ19), which show a loss of function of this core clock gene, are obese and hyperphagic and develop a myriad of metabolic symptoms including hyperglycemia, hyperinsulinemia, hepatic steatosis and dyslipidemia (76), all of which are significant markers of MetS.