To observe the effects of different concentrations of CTX on the expression of ERα and VASP mRNA in MCF‐7 and MDA‐MB‐231 breast cancer cells, cells were treated with 0, 0.05, 0.5, 5, and 10 μmol/L CTX for 24 hours, and harvested for detecting the mRNA expression levels of ERα and VASP by RT‐qPCR. Here, ESR1 is linked to breast cancer.