NRP1 and myeloid sarcoma: Neuropilin 1 (NRP1) is highly expressed in the brain endothelial cells of patients with MS, in particular in the early active demyelinating lesions;[204] and the interaction of IFN‐γ and NRP1 may contribute to the dysfunction of the BBB in MS.[204] Furthermore, secreted protein acidic and rich in cysteine (SPARC) is a cell‐matrix modulating protein that is involved in endothelial barrier function.