TGFB1 and heart failure: We specifically focused on platelet-derived TGF-β1 in a study of ART-linked cardiac dysfunction and fibrosis because: platelets contain 40–100 times the concentration of TGF-β1 as other cells; it is rapidly released upon platelet activation; it is a major component of circulating TGF-β1; and it contributes to cardiac fibrosis in a mouse model of heart failure [14,15].