Crm1 is a nucleocytoplasmic transport factor that is believed to interact with nucleoporins facilitating docking of the RRE-Rev-CRM1-RanGTP complex to the nuclear pore and the translocation of the complex across the nuclear pore complex (see Cullen 1998) Crm1 has been found in complex with two such nucleoporins, CAN/Nup214 and Nup88 which have been shown to be components of the human nuclear pore complex (Fornerod et al., 1997).