Several mutations in genes controlling the HPA axis—CRH, corticotropin-releasing hormone-binding protein (CRHBP), CRHR1 and CRHR2, glucocorticoid receptor (NR3C1), mineralocorticoid receptor (NR3C2), and FK506-binding protein 5 (FKBP5)—also play important roles in the development of cognitive dysfunction and mental illness [26]. The gene discussed is FKBP5; the disease is psychiatric disorder.