FUT4 and cancer: The authors had previously shown that in vitro transformation of epidermal fibroblasts generated cells expressing markers of cancer stem cells (CSCs), such as the Stage-Specific Embryonic Antigen 1 (SSEA1); these cells acquire multipotency, and the ability to proliferate indefinitely; moreover, when injected into mouse, they generated hierarchically organized tumors, where some cells retained the CSC potential, while others (SSA1 negative) gave rise to a progeny with moderate proliferating capacity [130].