DSPE-PEG2000-M2pep is a PEG compound which composed of DSPE and a M2-polarized macrophages targeting peptide (M2pep) . M2pep is conjugated to a proapoptotic peptide as monovalent or multivalent ligands to concentrate the toxic effect of the peptide to M2 macrophages. DSPE-PEG2000-M2pep can be used for drug delivery[1].