Methods of changing a phenotype of a cell are provided. The methods comprise increasing an amount of an amino acid sequence which is at least 70% identical to an amino acid sequence encoding an LMP protein or a fragment thereof in a cell. The cells may be contacted by either a composition comprising a nucleic acid sequence encoding the amino acid sequence which is at least 70% identical to the amino acid sequence encoding an LMP or its fragment or by a composition comprising acid sequence which is at least 70% identical to the amino acid sequence encoding an LMP or its fragment or any combination thereof. The cells may be contacted either in vivo or ex-vivo.