Pledgie-Tracy et al. have shown that 48 h incubation with 15 μm and 25 μm SFN down-regulated the protein expression of epidermal growth factor receptor (EGFR) and human epidermal growth factor-2 (HER-2) in MDA-MB-231, MDA-MB-468 and T47D cancer lines, while also down-regulating the protein expression of estrogen receptor (ER) in MCF-7 and T47D cells [113]. This evidence concerns the gene ESR1 and cancer.