CACNA1C, one of the genes strongly associated with BD, is involved in regulating circadian rhythms through L-type calcium channels (Ferreira et al., 2008; Sklar et al., 2008; Liu et al., 2011; Kumar et al., 2013; Fiorentino et al., 2014; Schmutz et al., 2014; Nudell et al., 2019). This evidence concerns the gene CACNA1C and Behcet disease.