Peptide sequence design and use thereof for peptide-mediated siRNA delivery

Peptides that have been found to facilitate the delivery of siRNA molecules into cells and to function in siRNA mediated silencing of cellular targets are disclosed. Complexes that include one of the peptides and a cargo molecule are disclosed, wherein the peptide and the cargo molecule are coupled non-covalently. Also disclosed are methods of producing and using the peptides/complexes.