While anti-TNFα therapy is exquisitely effective in RA, psoriasis and inflammatory bowel disease, it can worsen MS disease activity (The Lenercept Multiple Sclerosis Study Group and The University of British Columbia MS/MRI Analysis Group, 1999) or induce MS in individuals treated for systemic autoimmune conditions (Hare et al., 2014). This evidence concerns the gene TNF and myeloid sarcoma.