ESR1 and cancer: Cell viability assay findings indicated that ZER and ZERencapsulated in hydroxypropyl-β-cyclodextrin (ZER-HPβCD) inhibited the growth of estrogen receptor positivebreast cancer cells (ER+ MCF-7) at 72 h treatment with an inhibitory concentration (IC)50 of 7.51 ± 0.2 and 5.08 ± 0.2 μg/mL, respectively, and inhibited the growth of triple negative breast cancer cells (MDA-MB-231) with an IC50 of 14.96 ± 1.52 μg/mL and 12.18 ± 0.7 μg/mL, respectively.