Interestingly, recently, it has been shown that disruption of the circadian clock and expression of immune response genes encoding chemokine receptors (Ccr2, Ccr3, Ccr5, Ccr6, etc.)due to sleep deprivation make mice more susceptible to viral infections, highlighting the importance of environmental factors determining host immune responses against viral infections (206). The gene discussed is CLOCK; the disease is viral infectious disease.