,27,28 We therefore performed cis-eQTL mapping in CSF and peripheral CD4+ T cells, CD8+ T cells, and B cells, focusing on 2,499 prioritized genes which were upregulated in CSF, have been implicated in MS pathogenesis through susceptibility genome-wide association studies (GWASs),29 or have been identified as regulators of T cell migration to the CSF.30 The gene discussed is CD4; the disease is myeloid sarcoma.