LIN28 is a highly conserved, RNA-binding protein (RBP). It plays an important role as a translational enhancer, leading specific mRNAs to polysomes and therefore increasing the competence of protein synthesis. LIN28 was identified as a negative regulator of miRNA biogenesis and suggested to play a central role in blocking miRNA-mediated differentiation in stem cells and certain cancers. LIN28 is expressed by various undifferentiated embryonic cell types. Anti-LIN28 has been used as a sensitive marker for germ cell tumors. The positive staining of LIN28 in yolk sac tumors showed an advantage over OCT-4, which is negative in these tumors. The nuclear reactivity of this antibody may be observed in the myoepithelial cells of the salivary gland.