TGFB1 and breast cancer: In addition, activated HSCs suppress antitumor immune response by inducing T cell apoptosis and releasing TGF-β (46, 93), consistent with the well-established notion that immune suppression by CAFs is mediated by CXCL12 or nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4), leading to exclusion of CD8+ T cells85,86. Notably, HSCs can modify the extracellular matrix (ECM), thereby facilitating or impairing BC cell migration and invasion (89, 90).