FUT4 and cancer: Of interest, SSEA-1, a marker for early differentiation of human embryonic stem cells and a cancer stem cell marker in human and mouse brain tumors [26], was positive in HRAS-transformed cells but not in immortalized fallopian tube cells by immunofluorescent staining (Figure 5B), immunocytochemical staining (Figure 5C), and Western blotting (Figure 5D); no major difference in SSEA-1 expression was detected before or after CoCl2 treatment.