Throughout the journey from gene to protein, RNAs are encrusted with proteins that splice and dice sequences and inevitably regulate the processing and features of the final product. These nuclear sequence shufflings are implicated increasingly in mechanisms such as RNA-export to the cytoplasm, and nonsense-mediated decay (NMD), which detects and degrades RNAs with premature termination codons (PTCs). The role of splicing in export, however, remained largely unclear. Perhaps even more puzzling, NMD machinery in the cytoplasm needs to distinguish PTCs from legitimate stop codons. This suggested to some that mRNA can remember where its introns were after it leaves the nucleus.