He conducts research on circadian rhythms and on the “internal clocks” that generate these rhythms. People tend to become aware of their internal clocks in special situations, such as when experiencing jet lag. With chronic disruptions to a person’s internal clock (which can be caused, for example, by shift work) severe sleep or mood disorders may emerge, but also cancer, increased susceptibility to infections, metabolic syndrome, and other diseases. Nicolas Cermakian is studying the molecular mechanisms underlying circadian rhythms, how these clocks control physiology, including immune responses, and how clock dysfunction leads to disease.