Therefore, the aim of this first prospective study was to (1) explore whether IL-6 levels are associated with depression, (2) investigate whether MPO serum concentrations vary immediately and 6 months after AMI and (3) to investigate whether MPO is a significant predictor of AMI-induced depression, indicating the depression-associated suppression of the innate immune system. The gene discussed is IL6; the disease is depressive symptom measurement.