Pyruvate kinase isoform 2 (PKM2) is a glycolytic enzymeexpressed in T cells infiltrating the central nervous system in a mouse model ofMS, suggesting PKM2 modulation could provide a new avenue for MS therapeutics.In a recent article in Science Signaling, Seki et al. show thatpharmacological modulation of PKM2 alters but does not ameliorate disease in amouse model of MS. Here, PKM is linked to myeloid sarcoma.