Williams et al. showed that elevated levels of TNF are found in the serum and CSF of patients with MS, and it shows a positive correlation with symptom severity [8]. Kollias and Kontoyiannis concluded from the results of murine disease models that TNF alpha receptor exerts its effects via two receptors, TNFR1 and TNFR2, both carrying contradictory effects [18]. This evidence concerns the gene TNFRSF1A and myeloid sarcoma.