The large number of CNS and peripheral demyelinating disorders after TNF-α blocker administration published in the literature [2, 30, 49–54, 55•, 56, 57••, 58–90, 91•, 92••, 93] and the 2 clinical trials of TNF-α blockers in MS patients showing an increase of demyelinating events [22, 23] raise the question of a possible association. Here, TNF is linked to myeloid sarcoma.