It is worth highlighting that higher concentrations of an active form of a cancer-derived form of TGF-β1 in patients with gastric adenocarcinoma correlated positively with urokinase (uPA) activity [15], supporting the predominant role of plasmin in TGF-β activation in the tumour microenvironment postulated in this review. Here, TGFB1 is linked to gastric adenocarcinoma.