The 17 target genes in the androgen and estrogen synthesis and metabolism pathway (including CYP3A4) regulate four reactions that hydrolyse oestrone, testosterone, and pregnenolone into products that have been described to bind estrogen or androgen receptors and induce proliferation in breast cancer cells [36] (Supplementary File S1, Table S11, Supplementary File S2, Figure S8). This evidence concerns the gene CYP3A4 and breast cancer.