Transduction of primary DRG neurons in culture with S4IL4 (Figure 1a) at a multiplicity of infection (MOI) of 1 resulted in the production and release of substantial amounts of IL-4 into the medium as detected by ELISA (110 pg/ml over 24 hrs from cells infected with S4IL4 compared to 10 pg/ml from cells infected with control vector SHZ). This evidence concerns the gene IL4 and infection.