SAHA reversed DLB and restored mitochondrial function in the heart via an effect on NOX-4 and mitochondrial biogenesis gene (PGC-1α and Nrf-2) expression levels. The authors speculated that when fluoxetine lacks effectiveness on cardiac mitochondrial biogenesis and cardiac NOX-4 gene expression, patients with depression may develop a recurrence of their depression. The gene discussed is NOX4; the disease is depressive symptom measurement.