used RABID‐seq, which enables the concurrent examination of cell–body interactions and single‐cell transcriptomes, and studied MS patient samples to identify signalling pathways controlled by the axon guiding molecules Sema4D‐PlexinB1, Sema4D‐PlexinB2 and Ephrin‐B3/EphB3, which act as key mediators of microglia–astrocytic interactions that promote the pathogenesis of the CNS.191. This evidence concerns the gene SEMA4D and myeloid sarcoma.