FUT4 and Arrhythmia: Recently, hESC-derived differentiated cells expressing cardiac transcription factors Insulin gene enhancer protein (Isl-1) and Stage Specific Embryonic Antigen-1 (SSEA-1) when transplanted into the infarct site of 68-year-old patients with impaired left ventricular EF showed significant improvement in left ventricular function without complications like arrhythmias, tumor creation, or detrimental immunosuppression [24].