CD4 and myeloid sarcoma: Recently, Planas and colleagues (155) identified a ubiquitous enzyme, guanosine diphosphate (GDP)-L-fucose as a potential MS autoantigen recognized by a Th2-like CD4 cell clone expanded in MS brain lesions and by CSF-infiltrating CD4 Th1-like cells from HLA-DRB3*-positive patients, and showed crossreactivity with an immunodominant MBP peptide and homologous peptides from gut microbiota.