Using endothelial monolayers and mouse models, Wu et al. found that TGF-β1-mediated NSCLC-derived exosomes alter the tight junctions and increase BBB permeability to promote NSCLC brain metastasis via the miRNA-1207-5p/EPB41L5 axis, where the overexpression of lnc-MMP2-2 in brain endothelial cells increased vascular permeability and the inhibition of lnc-MMP2-2 alleviated these effects. Here, MMP2 is linked to non-small cell lung carcinoma.