ESR1 and cancer: Nuclear EGFR is associated with poor prognosis in several cancer types.45, 46, 47, 48, 49 Cancer cells also utilize nuclear-cytoplasmic transport of tumor-suppressive proteins, such as retinoblastoma, APC, p53, BRAC1, FOXO proteins, INI1/hSNF5, galectin-3, Bok, nucleophosmin, RASSF2, Merlin, p21CIP, p27KIP1, N-WASP/FAK, estradiol receptor and Tob, drug targets topoisomerase I and IIa and BCR-ABL, and the molecular chaperone protein Hsp90, through the nuclear pore complex of a cell.50