CD47 can interact with signal regulatory protein alpha (SIRPα) on the monocytes/macrophage membrane to constitute a “don't eat me” signal, blocking the uptake of clnFTY by monocytes/macrophages, and enhancing its circulation in vivo (Figure 1).[15] Owing to the efficient delivery of FTY720 to LNs, clnFTY nanoparticles efficiently inhibited lymphocyte infiltration of the CNS and alleviated injury in the EAE mice, which is the most frequently used model in MS research. This evidence concerns the gene SIRPA and myeloid sarcoma.