Since gastrin-releasing peptide in the basolateral amygdala has been implied in conditioned fear [55], and CCK-4 and its synthetic analogue tetragastrin have been shown to potently induce panic attacks via the CCK-B/CCK-2 receptor [56], it could be speculated that, in analogy, the presently identified decreased methylation at the GAST gene, potentially increasing gene expression, might be involved in anxiety disorder pathogenesis as well. This evidence concerns the gene CCKBR and anxiety disorder.