In breast cancer, TGF-β signalinggets hyper activated thus promoting cancer progression and metastasis.In work by Zhang et al., a particular type of bioresponsive NPs-rotaxane-doxorubicin-heparin-SB431542(R (D)/H(S) NPs), were designed by β-cyclodextrin-grafted heparinand pH-responsive pseudorotaxane to produce enhanced chemotherapeuticefficacy on breast cancer via TME modulation. Here, TGFB1 is linked to breast cancer.