High aromatase expression has been also observed in the eutopic endometrium as well as in endometriosis implants.5 This enzymatic imbalance is thought to raise oestrogen activity into the endometriotic lesion, maintaining the loop between local hyperoestrogenic state, inflammation and proliferation and survival of endometriotic implants.6 Endometriosis current treatment is thus mainly based on suppression of oestrogen production. This evidence concerns the gene CYP19A1 and endometriosis.