BRCA1 and breast cancer: It has been reported that AhR (aryl hydrocarbon receptor) could bind with the promoter (chr 17: 43125372–43125499) of BRCA1 and inhibit BRCA1 transcription in MCF7, UACC3199, and HCC38 BC cell lines.[49] However, whether and how AhR affected BRCA1 transcription in human trophoblast cells was unknown.