Ambiguously, a study from Nakshatri et al. showed that ER-positive breast cancer cells such as MCF-7, T47-D or ZR-75 cells express an elevated COUP-TFII expression, while ER-negative cells such as MDA-MB-231 and SkBr3 express a low level of this receptor [43]. The gene discussed is ESR1; the disease is breast carcinoma.