Studies also show that a subgroup of MDD patients characterized by high blood levels of CRP and IL-6, have a suboptimal response to antidepressants with predominantly serotonergic action, but a better response when combining antidepressants with anti-inflammatory agents such as infliximab (Arteaga-Henríquez et al., 2019). The gene discussed is CRP; the disease is major depressive disorder.