There is provided peptides for inhibiting growth of cancer cells, the peptides comprising the amino acid sequence RxKxKxxxxR wherein K and R are respectively lysine and arginine amino acid residues, each x is independently an amino acid, and 5 wherein the peptide has 50% or less amino acid sequence identity with the amino acid sequence RSKAKNPLYR (SEQ ID. No. 2). Each x amino acid may independently be an amino acid residue selected from the group consisting of alanine (A), valine (V), leucine (L), isoleucine (I), threonine (T) and serine (S) amino acid residues. There is also provided chimeric proteins incorporating a peptide of the amino acid sequence 10 RxKxKxxxxR, nucleic acids encoding for the peptide, expression vectors including a nucleic acid encoding the peptide for expression of the peptide, and methods for use of the peptide for inhibiting growth of cancer cells.
