S100A9 and ischemia: First, it is reported that MRP14 is predominantly expressed in neutrophils and monocytes in peripheral blood, with only limited expression in brain parenchymal microglia.[27] In peripheral blood, MRP14 constitutes ≈45% of the total cytosolic protein in neutrophils, while monocytes express ≈40‐fold lower levels.[28] Second, neutrophils reach their peak infiltration 1–2 days post‐ischemia, corresponding with the increase in brain MRP14 expression observed in our study.