EGR1 and major depressive disorder: In light of the tight link between EGR1 expression and neuronal plasticity, the down-regulation of EGR1 in the PFC of depressed patients is particularly interesting and could represent one of the substrates for the anatomical and functional alterations observed in major depressive disorders in this brain area (Krishnan and Nestler, 2008; Koenigs and Grafman, 2009; Lefaucheur et al., 2017).