TNF and myeloid sarcoma: 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].