The exact mechanisms underlying the protective role for RAC2 in MS risk has not yet been elucidated; however, an association between RAC2 and MS has previously been reported.32,35 For example, the expression level of RAC2 in whole blood samples from patients with MS were found to be low compared with those in healthy controls.35 This finding supports the protective role of RAC2 on MS risk that we observed in the current results. Here, RAC2 is linked to myeloid sarcoma.