In immortalized human endometrial cell lines, Bruner et al. partially elucidated the mechanistic processes that link EDCs and endometriosis, such as steroidogenic factor 1 gene (SF-1) overexpression causing excessive production of estrogen via high levels of ER-β, progesterone resistance, oxidative stress and pro-inflammatory conditions, which are thought to be involved in the migration, adhesion and progression of endometrial tissues [33]. The gene discussed is ESR2; the disease is endometriosis.