Several reports showed that CAFs promote tumour progression and resistance to chemotherapy by secreting various growth factors and inflammatory chemokines.4, 5 In this study, the level of PAI‐1 and TGF‐β secreted after suppression of the MF characteristics of CAFs by PAI‐1 inhibition was significantly lower than that from CAFs without PAI‐1 inhibition. This evidence concerns the gene TGFB1 and neoplasm.