THBS1 and cancer: This induced expression of TGF-β1 in cancer cells, along with the enhanced expression of enzymes (plasmin, MMPs) and other cancer-associated triggers that activate latent TGF-β1 (integrins and TSP-1, ROS), as described earlier, serve tumors with elevated levels of active TGF-β1 that aid cancer cells to grow, survive, and metastasize.