Our findings and others44,52,53 suggest a potential mechanism for leukocyte recruitment not only intravascularly by endothelial cells30, but also at the brain perivascular space, aligning with recent observations of vascular and perivascular accumulation of CD8+ T-cells in the brain microvasculature in post-mortem samples of CM patients54,55. This evidence concerns the gene CD8A and cutaneous mastocytosis.