CD8A and breast cancer: To evaluate the function of VLA-4 in breast cancer LM, we applied neutralization antibody against VLA-4 and found that VLA-4 blockade decreased the number of CD8+ T cell in meninges (Figure 5C), and aggregated intracranial tumor metastasis, determined by histopathology (Figure 5D) and BLI signaling (Figure 5E and F).