We observed that ENG suppression by shRNA in myCAFs not only attenuated TGF‐β‐Smad2/3 signaling and TGF‐β1 production but also inhibited the ability of these fibroblasts to promote tumor growth when co‐injected with human breast cancer cells subcutaneously into recipient mice. This evidence concerns the gene TGFB1 and breast carcinoma.