Only three studies have been performed in relapsing RR-MS patients, and these studies showed that CD39 expression in PBMCs from RR-MS patients was similar to16 or higher19 than that in healthy subjects, and that the frequency of CD39-expressing Treg cells was increased19 or did not change16,18 in RR-MS patients compared with controls. Here, ENTPD1 is linked to myeloid sarcoma.