Leptin may modulate the MS inflammatory process during relapses.5 In a study by Batocchi et al., an increase of leptin was observed before the first clinical exacerbation in relapsing patients, but after two months of INF-beta therapy, leptin significantly decreased.6 Therefore, they suggested that leptin be considered as a marker of disease activity.6 They found that leptin has serum levels in RRMS patients, in a stable phase of the disease, which is comparable with healthy subjects. Here, LEP is linked to myeloid sarcoma.