Method for enhancing the effciency of gene transfer with stem cell factor (SCF) polypeptide

A method of enhancing the efficiency of transfer of a polynucleotide into a target mammalian cell in vitro, the method comprising:

• (a) obtaining the target cell from a mamalian donor wherein the target cell expresses a stem cell factor (SCF) receptor;
• (b) exposing the target cell obtained in step (a) to an effective dose of a biological active SCF polypeptide or biologically active analog or fragment thereof, which induces cell proliferation;
• and
• (c) introducing the polynucleotide to the target cell of step b) in vitro
• wherein the exposure of said SCF polypeptide to said target cell results in increased uptake of the polynucleotide into the cell.