Lin-28 acts as a 'translational enhancer', driving specific mRNAs to polysomes and thus increasing the efficiency of protein synthesis. It is marker of undifferentiated human embryonic stem cells and has been used to enhance the efficiency of the formation of induced pluripotent stem (iPS) cells from human fibroblasts. It 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.