CLOCK and Behcet disease: Consistent with the ClockΔ19 mutant, Afh (After-hours) mice which carry a mutation in the clock-gene Fbxl3 thereby preventing Cry (1/2) degradation, display significantly altered rhythms and a mania-like phenotype [19–21], further reinforcing a strong link between period length and mood-related behaviors, and by extension BD and clock genes.