Eukaryotic gene expression is controlled by multiple mechanisms, and its regulation is central for physiological responses to extracellular and intracellular signals. An essential step in this process involves the movement of mRNA transcripts from the site of synthesis in the nucleus to the cytoplasm, where they can be translated into proteins. The nuclear export of mRNA transcripts can be broken down into distinct stages: first, pre-mRNA is transcribed in the nucleus, where it is processed and packaged into messenger ribonucleoprotein (mRNP) complexes; second, the mRNPs are targeted to and translocate through nuclear pore complexes (NPCs) that are embedded in the nuclear envelope; and third, the mRNPs are directionally released into the cytoplasm for translation. Recent work has revealed that there is extensive mechanistic coupling between each of these steps (Kohler and Hurt, 2007). Moreover, it has been shown that perturbations in the factors that are essential for mRNA nuclear export have surprising links to different disease states. In this article and its accompanying poster, we provide an overview of the mRNA nuclear export pathway. FIG1