CYP19A1 and breast cancer: We also show that the change in aromatase expression levels is mediated via aberrant transcriptional regulation of the CYP19A1 gene; in breast adipose by increases in gonad and breast cancer-specific promoter II/I.3 and promoter I.4 transcripts; and in the ovary with elevation in breast cancer-specific promoter I.3 and promoter II transcripts.