Given the known role of Slc4a4 in transporting arginine-rich peptides,52 we chose arginine metabolism as one of Slc4a4’s downstream pathways to further investigate whether increased citrulline/NO production from arginine metabolism contributes to elevated CCL2 levels and stroke-induced BBB damage in the absence of astrocytic Slc4a4. Here, CCL2 is linked to stroke disorder.