BSN and myeloid sarcoma: Next, we developed an ELISA with knockout-validated antibodies for the presynaptic protein Bassoon (BSN) and quantified BSN in the cortex, spinal cords and plasma of EAE mice and in the CSF (total n = 30) and serum (total n = 146) of an observational cohort study with people with MS (pwMS) and controls.