Th17-related molecules were shown to correlate with parameters of disease activity in MS. In vitro studies demonstrated that the amount of IL-17 (and also IL-5) produced by mononuclear cell cultures from patients with MS after stimulation with human myelin basic protein correlates with the number of active lesions on magnetic resonance imaging (MRI) [53]. The gene discussed is IL17A; the disease is myeloid sarcoma.