FOLR1 and breast carcinoma: Interestingly, high FRα expression in lung adenocarcinoma was found to be associated with early stage disease and favorable prognosis [20, 27]; in contrast, high FRα expression was shown to be associated with poor prognosis in breast cancer [28, 29] (but not relative to breast cancer brain metastases) [21], and with poor disease-free and overall survival, as well as chemoresistance in ovarian cancer [30–32].