We aim at assessing any association between patient prognosis and the pathways controlling the intracrine estrogen generation in EC: (a) the balance between 17β-hydroxysteroid-dehydrogenase-type 1 (HSD17B1), that generates active estrogens, and HSD17B2, converting active into poorly active compounds; (b) the balance between steroid sulphatase (STS, that activates estrogens) and estrogen-sulphotransferase (SULT1E1, that deactivates estrogens); (c) the levels of aromatase (ARO), that converts androgen into estrogens. mRNA levels of HSD17B1, HSD17B2, STS, SULT1E1 and ARO were determined among 175 ECs using cDNA microarray.