ESR1 and breast carcinoma: Another study reported a cytotoxic effect of alizarin on MGC- 803 with an IC50 of 40.35 μM (Yao et al. 2014; Huang et al. 2017a, b), concluding that alizarin is a potent cytotoxic agent especially on ERα positive breast cancer and bone cancer (Mishra et al. 2017).