ACTA1 and gastric cancer: Our data suggest possible CAF–SERPINE1 crosstalk, evidenced by: (1) CAFs exhibited higher SERPINE1 secretion than normal fibroblasts; (2) co-culture with CAFs induced SERPINE1 upregulation in GC cells; and (3) a positive correlation was observed between α-SMA and SERPINE1 expression in GC patients, especially in those with stage III disease.