The nuclear pore complex (NPC) is an essential gateway between the cell nucleus and the cytoplasm. The NPC is formed by multiple copies of ∼30 different proteins called nucleoporins, which can be divided into scaffold, membrane-anchored and barrier components. Thousands of phenylalanine-glycine (FG) repeats, found in barrier nucleoporins, interact to form the selective permeability barrier of the NPC channel. Shuttling nuclear transport receptors are able to interact with these FG repeats and mediate the passage of large macromolecular cargoes through the barrier. Combinations of shuttling receptors, their adaptors and localisation signals in cargo molecules define a wide array of nuclear import and export pathways. Recent research has pointed to some dynamic features in NPC components, as well as a number of nucleoporin-related human diseases which are characterised by highly cell-type-specific phenotypes.