Zhang et al. discovered that ZEB1 mechanistically inhibited ER-α transcription through the ZEB1/DNA methyltransferase 3B (DNMT3B)/histone deacetylase 1 (HDAC1) complex binding to hypermethylate and silence the ER-α promoter, subsequently attenuating the responsiveness of breast cancer cells to antiestrogen treatment [87]; these results indicate that ZEB1 is a key determinant of antiestrogen resistance in breast cancer. Here, HDAC1 is linked to breast cancer.