FKBP5 and post-traumatic stress disorder: Especially relevant in the context of preventive approaches for the management of chronic pain, early work from Klengel et al. indicated the potential that early life trauma in humans may lead to a decrease in FKBP5 DNAm, an epigenetic change that primes FKBP5 for hyper-responsiveness and may increase the susceptibility to post-traumatic stress disorder (PTSD) in adulthood [21].