While the bulk of cellular mRNA is known to be exported by the TAP pathway, export of specific subsets of cellular mRNAs may rely on chromosome region maintenance 1 (CRM1). One line of evidence supporting this hypothesis comes from the study of mRNAs of certain early response genes (ERGs) containing the adenylate uridylate-rich element (ARE) in their 3′ untranslated regions (3′ UTRs). It was reported that HuR-mediated nuclear export of these mRNAs was CRM1-dependent under certain stress conditions. To further examine potential CRM1 pathways for other cellular mRNAs under stress conditions, the nuclear export of human interferon- α 1 ( IFN- α 1 ) mRNA, an ERG mRNA induced upon viral infection, was studied. Overproduction of human immunodeficiency virus type 1 Rev protein reduced the expression level of the co-transfected IFN- α 1 gene. This inhibitory effect, resulting from nuclear retention of IFN- α 1 mRNA, was reversed when rev had a point mutation that made its nuclear export signal unable to associate with CRM1. Leptomycin B sensitivity experiments revealed that the cytoplasmic expression of IFN- α 1 mRNA was arrested upon inhibition of CRM1. This finding was further supported by overexpression of ΔCAN, a defective form of the nucleoporin Nup214/CAN that inhibits CRM1 in a dominant-negative manner, which resulted in the effective inhibition of IFN- α 1 gene expression. Subsequent RNA fluorescence in situ hybridisation and immunocytochemistry demonstrated that the IFN- α 1 mRNA was colocalised with CRM1, but not with TAP, in the nucleus. These results therefore imply that the nuclear export of IFN- α 1 mRNA is mediated by CRM1. However, truncation of the 3′ UTR did not negatively affect the nuclear export of IFN- α 1 mRNA that lacked the ARE, unexpectedly indicating that this CRM1-dependent mRNA export may not be mediated via the ARE.