NR3C1 and post-traumatic stress disorder: Given recent work examining epigenetic risk factors associated with the development of PTSD, we now review work employing animal models of epigenetic regulation of anxiety and fear associated genes which has been translated into human clinical populations, including epigenetic modifications of glucocorticoid receptor (GR) function including FKBP5, Nr3c1, and the BDNF pathways.