More precisely, locating the major selective barrier to nucleocytoplasmic export and a refinement of the measure of transport kinetics are important contributions to the understanding of the details of NPC’s role in mRNA export and other vital cellular processes, such as mislocalization of cytoplasmic proteins to the nucleus and deregulation of signaling pathways can have disastrous consequences (such as developmental defects or cancer) and directly or indirectly involve the interaction of the NPC with various proteins [63,64,65,66,67]. This evidence concerns the gene NPC1 and cancer.