CACNA1C and Behcet disease: Lower cortical thickness in parietal and frontal cortices was also described in individuals with BD carrying the CACNA1C risk allele (Smedler et al., 2019); furthermore, a clinical study found that altered CACNA1C expression significantly affected the intrinsic spontaneous calcium activity of neural progenitors that play a crucial role in brain development, suggesting that CACNA1C may act as a molecular switch that increases susceptibility to psychiatric disease (Smedler et al., 2022).