We selected SLC6A4/5HTT, a well known serotonin transporter gene associated with depression vulnerability and a target of most antidepressant treatments [14,15], S100A10, another potential marker of antidepressant effect encoding p11 [16-18], PDLIM5, encoding a protein associated with mood disorders [19,20], and several cytokines/chemokines playing important roles in regulating immune-inflammatory processes (CCL2, IL1B, IL6, IL8, IL10 and TNF) [21]. The gene discussed is SLC6A4; the disease is major depressive disorder.