Accordingly, it has been observed that global 3'UTR shortening correlates with high proliferative rates whereas lengthening occurs during cell differentiation.24The 3'UTR of ZEB1 is particularly long (~2500 nucleotides) and contains putative binding sites for many microRNAs, including members of the miR-200 family that repress its expression in cancer epithelial cells.25 Genotoxic stress caused shortening of the 3'UTR, with selective depletion of transcripts terminating at the distal PASs (p2 and p3) in cells treated with gemcitabine. This evidence concerns the gene ZEB1 and cancer.