Circadian oscillation of biological processes has been described in most of the light-sensitive organisms. There is a growing body of evidence for connection between a number of metabolic pathologies and the circadian clockwork. We have set up the experimental system for long-term recording of circadian reporter oscillations in human primary cultured cells from different tissue types, and revealed the presence of a robust circadian oscillator in human pancreatic islets and islet cells using this approach. The prevalence of obesity and diabetes in modern society is taking on enormous proportions. It is therefore of major importance to identify the molecular basis of circadian rhythmicity in human peripheral tissues in physiological conditions, and upon obesity/T2D. Furthermore, we explored the molecular makeup of human thyroid clock, and its potential roles in thyroid malignancies. This approach might bring new insights into the role of circadian clocks in thyroid cancer, and have important clinical perspectives.