The story of HIV-1 and RNA helicases is, however, likely to be more complex than and unlikely to conclude simply with RHA, RH116, DDX1 and DDX3 (Figure 1 ). HIV-1 RNAs are extensively regulated through splicing. Splicing is a multiple-step process requiring the recognition of splice sites by spliceosomes. It is generally believed that remodeling of RNA-RNA and RNA-protein interactions within the spliceosome is catalyzed by a family of DEAD/DExH box RNA helicases. To date, seven mammalian proteins that are RNA helicases have been implicated in mRNA splicing (67, 68) . Whether there is specific preference by subclasses of RNA helicases for viral mRNA splicing remains to be clarified. Moreover, how cellular RNA helicases might contribute to the translation of viral mRNAs also require further investigation.