In addition, Our finding that IL-6 is a downstream target of COX2 may also explain earlier observations that sphingosine-1-phosphate markedly induces COX2 expression and IL-6 secretion in human tracheal smooth muscle cells [37], and that administration of celecoxib significantly reduces serum IL-6 levels in patients with major depressive disorder [38]. The gene discussed is PTGS2; the disease is major depressive disorder.