In several genetic studies researchers linked FK506 binding protein 5 (Fkbp5) to stress-related diseases and phenotypes such as major depression, posttraumatic stress disorder, and recovery from psychosocial stress (Binder et al. 2004; Zimmermann et al. 2011; Klengel et al. 2013). Here, FKBP5 is linked to major depressive disorder.