In recent years, both clinical observations and experimental studies have shown that the therapeutic efficacy of anticancer drugs can be altered by steroid hormones and their receptors, but the potential molecular mechanisms remain unclear.34, 35, 36 In this study, using our established paclitaxel‐resistant breast cancer cells, we explored whether and how IBC influenced paclitaxel resistance in breast cancer cells via the ERα‐dependent pathway. The gene discussed is ESR1; the disease is breast cancer.