A key finding of Setiawan et al. was that duration of untreated MDD significantly correlated with TSPO VT in three of the examined regions (prefrontal cortex, anterior cingulate cortex, and insula), and that disease duration was a predictor for greater TSPO expression in MDD patients (Setiawan et al., 2018). The gene discussed is TSPO; the disease is major depressive disorder.