However, questions remain, such as those related to the functional role of ANGPTL4 in BM and transcriptional regulation of ANGPTL4. One possible mechanism for ANGPTL4 facilitation of breast cancer brain metastasis is through disrupting vascular endothelial junctions, much like the mechanism for ANGPTL4 facilitation of breast cancer lung metastasis.21 Another potential mechanism includes ANGPTL4 binding to integrins β1 and β5. Here, ANGPTL4 is linked to breast cancer.