Alterations in gene expression are central to the malignant phenotype. In this 
issue, Al-Ahmadi et al elegantly demonstrate that one key mechanism that 
determines invasiness in breast cancer is likely to be dysregulation of mRNA 
stability. This is achieved by altered expression of the proteins TTP and HuR, 
which bind 3' untranslated region (UTR) elements in cancer-related genes. The 
authors link this to the expression of a miRNA, miR-29a, and show that 
anti-miR-29a treatment can reverse the invasive phenotype in vitro. This further 
highlights the important roles of mRNA UTRs in malignant transformation, and the 
importance of investigating post-transcriptional disease mechanisms. Such 
mechanisms have the potential to provide novel therapeutic targets, as well as 
being vital to further our understanding of cancer biology.