This is in line with a recent meta-analysis of the incidence of seizures in individuals with MS participating in randomized clinical trials of DMTs, which found that sphingosine-1-phosphate receptor (S1PR) modulators, including fingolimod, were associated with more than a twofold increase in the risk of seizures when compared with placebo or comparators.26 Given the wide distribution of S1PRs in the CNS, it remains to be explained whether the effect of S1PR modulators on neuronal excitability may explain this observation. Here, S1PR1 is linked to myeloid sarcoma.