In this regard, although epigenetic findings are still exploratory, epigenetics could represent a novel kind of biomarker for ECT treatment response, also in combination with more established predictors; certainly, more research is needed before reliable conclusions can be reached, and other biological systems implicated in the pathophysiology of MDD, aside from BDNF signaling, represent possible targets for future epigenetic studies. The gene discussed is BDNF; the disease is major depressive disorder.