However, this difference in osteolytic BMET potential between ER+ tumor cells provides evidence that the pro-osteolytic effects of E2 signaling in bone-disseminated ER+ breast cancer cells are likely also interdependent on other cellular transformations and signaling pathways present in ER+ tumor cells within the bone microenvironment - a postulate that awaits further testing. The gene discussed is ESR1; the disease is breast cancer.