Inflammation is highly fluctuating and/or situational in MS, even in the RR group alone as, for instance, increased levels of GFAP were found in a cohort of MS patients (compared with controls) but once you start to depict the subgroups you may find that the results are due to an increase at relapse in RR MS, as compared with stable or even progressive MS (118). Here, GFAP is linked to myeloid sarcoma.