Given that there are only few data on the significance of ERR protein levels in ovarian cancer, in this study, we examined protein expression of ERRα, β and γ in 208 ovarian cancer samples, performed correlation analyses with ovarian cancer markers, steroid hormone receptors and other cancer-associated genes and finally performed Kaplan–Meier analyses to elucidate the effect of their expression levels on survival of ovarian cancer patients. Here, SLC7A1 is linked to cancer.