ANGPTL4 and triple-negative breast carcinoma: The BCBM is promoted by the interaction of astrocytes in the brain and the invading triple-negative breast cancer cells via TGF-β2 (Transforming Growth Factor-beta-2) produced by astrocytes and is responsible for ANGPTL4 expression upregulation/angiopoietin-like 4 (ANGPTL4) [55].