Transport of mRNA through the Nuclear Pore Complex (NPC) is a dynamic process involving distinct machinery and receptor subsets. The separation of the two compartments and the regulation of this transport provide spatial and temporal control over mRNA expression and ultimately control over translation. It should be noted that mRNA export does not rely on a specific motif in the mRNA molecule, but rather transport appears to be coupled to processing and regulation. The specific proteins that are bound to the mRNA determine when it will be transported to the cytoplasm. This limitation insures that transport overwhelmingly favors transport of fully processed mRNA molecules.