Fluoxetine, a selective serotonin reuptake inhibitor, suppresses the production of IL-17, IFN-g, and GM-CSF, but not IL-21, by activated CD4+ T cells in vitro, and blockade of 5-HT2B-receptors with specific antagonist reduced the inhibitory effect of fluoxetine on IL-17, IFN-γ, and GM-CSF production in MS patients [137]. This evidence concerns the gene CD4 and myeloid sarcoma.