LIN28 is one of the four key human factors (OCT4,SOX2,NANOG and LIN28) used to reprogram human fibroblasts to an embryonic stem (ES) cell-like state known as the induced pluripotent stem (Ips) cell. Lin28 is a marker of undifferentiated human embryonic stem cells and a cytoplasmic Mrna-binding protein that binds to and enhances the translation of the IGF2 Mrna. LIN28 has also been shown to bind to the let-7 pre-miRNA and block production of the mature let-7 microRNA in mouse embryonic stem cells.