IGF-II mRNA-binding proteins (IMP) bind RNA and influence RNA synthesis and metabolism. IMPs, IMP-1 (coding region determinant-binding protein/insulin-like growth factor II mRNA-binding protein, CRD-BP, VICKZ1), IMP-2 (IMP2, VICKZ2, p62) and IMP-3 (KOC1, VICKZ3), contain a unique combination of RNA recognition motifs and four hnRNP K homology domains. IMP-1 is abundant in embryonal tissues and in 81% of colon cancers, 58.5% of breast cancers and 73% of sarcomas. IMP-1 recognizes c-Myc, IG