While no membrane or cytoplasmic FRα staining was observed in a broad range of normal tissues evaluated by IHC (Fig. 2), around half of ovarian tumour samples expressed FRα, either in the cytoplasm, on the cell membrane, or both, with 60% of the high-grade serous tumours being positive for FRα expression (Figs. 2 and 3). Here, FOLR1 is linked to ovarian neoplasm.