Provided herein are methods for facilitating or inducing stable transgene integration and expression in a proliferating cell, comprising administering to the cell (i) a recombinant AAV (rAAV) vector comprising the transgene flanked by transposon-derived inverted terminal repeat sequences, which sequences are in turn flanked by AAV-derived inverted terminal repeat regions, and (ii) a source of a transposase that recognises said transposon-derived inverted terminal repeat sequences and directs the genomic integration of the transgene into the genome of the proliferating cell. Also provide are methods and transgene delivery systems for the treatment or prevention of diseases affecting, associated with or characterised by proliferating cells.