The nuclear envelope protects and organizes the genome. The nuclear pore complexes embedded in the nuclear envelope allow selective transport of macromolecules between the cytosol and nucleoplasm, and as such help to control the flow of information from DNA to RNA to proteins. A growing list of integral membrane proteins of the nuclear envelope are described to function in the organization of the genome, as well as the assembly of the NPCs. Here, we discuss how the nuclear pore complex may sort these proteins to obtain a specific protein composition of the inner membrane.