S100A9 and stroke disorder: Recent studies have shown that reactive microglia can phagocytose and clear infiltrating peripheral neutrophils recruited to the ischemic brain, thus playing a pivotal role in protecting against neutrophil‐induced tissue damage after stroke.[11] Our findings suggest that MRP14 acts as a “don't eat me” signal, protecting neutrophils from microglial phagocytosis post‐stroke.