It was reported in 2001 that co-expression of the mutant 4E-BP1, which was altered at five different amino acid positions that are normally the targets for phosphorylation, up-regulated the expression of p27 through 5'-untranslated region (5'-UTR) in the proximal upstream region of p27 gene in D6P2T Schwannoma cells [35]. This evidence concerns the gene CDKN1B and schwannoma.