NRG1 and major depressive disorder: In the GSE99725 dataset, the NRG1 was up-regulated in HCs compared to MDD patients (FC = 0.07, p = 0.04) before and after (FC = 0.11, p = 0.03) surgery, however, it didn't show a significant variation (p > 0.05) once comparing MDD patients before and after surgery.