Figure 1. CLOCK-controlled gene expression in skin has a circadian pattern and correlates with synchronized hair growth cycles.

A schematic diagram showing rhythmic circadian expression of clock controlled gene Dbp over different phases of the hair growth cycle (solid line). The circadian amplitude of Dbp expression correlates with progression of the hair follicle cycle with highest expression during telogen (broken line). Skin histology for representative hair growth cycle stages is shown below. Note that this schematic does not show the actual length of each phase of the hair growth cycle.