MAPK1 and myeloid sarcoma: In MS, the disappointing results of phase II clinical trials with Ustekinumab (CNTO 1275, Stelara®), a human monoclonal antibody targeting the interleukin (IL)-12/23 p40 subunit [23], may suggest that pleiotropic and redundant mediators of the immune response such as cytokines, while being pathogenetically relevant through processes that may last several years, are impractical targets for single therapies that ought to be effective in a relatively short time interval.