These results strongly suggested that α-SMA-positive CAFs provide some growth-promoting signals to neighbouring cancer cells, which led to tumour regrowth, and the difference in the potencies of the treatments for reducing such tumour-promoting α-SMA-positive CAFs can account for their different antitumour activities in terms of the suppression of regrowth between treatment with E7130 and CTX and treatment with paclitaxel and CTX. Here, ACTA1 is linked to cancer.