HSD17B1 and endometriosis: Thus, our goals were to study the relationship between gene and protein expression of aromatase (CYP19A1 or ARO), steroid sulfatase (STS), and hydroxysteroid 17-beta dehydrogenase (HSD17B1) in superficial (SUP), ovarian (OMA), and deep infiltrating (DIE) endometriotic lesion sites as well as in the eutopic endometrium of patients with (EE) and without (control) endometriosis in the same and large cohort of patients.