BRCA1 and breast cancer: In particular, the isoflavone genistein from soy was showed to hamper TCDD-dependent downregulation and methylation of BRCA-1, whose alteration is known to play a pivotal role in the onset of breast cancer, along with decreasing levels of DNMT-1 and cyclin D1 in MCF-7 cells, proving the role of genistein in counteracting ER (estrogen receptor) α-positive breast cancer cells via antagonizing AhR [225].