ESR1 and breast cancer: The subsequent results justified that inhibition of ERα‐mediated IGF‐1/AKT/mTOR signalling contributes to CPT's inhibitory effect on ERα‐positive breast cancer cells by the data that compared with sh‐RNA control, sh‐ERα MCF‐7 cells shows a little bit of resistance to CPT as the p‐S6K1 and 4E‐BP1 was partially reversed with increased expression of p‐AKT(S473) and p‐AKT(T308).