In {HEAD ~ one aspect}, the invention includes a composition for treating a tumor in a subject, comprising liposomes composed of a vesicle forming lipid and between about 1 20 mole percent of a vesicle forming lipid derivatized with {TAIL ~ a hydrophilic polymer} 
In { HEAD ~ one aspect } , the invention includes a composition for treating a tumor in a subject , comprising liposomes composed of a vesicle forming lipid and between about 1 20 mole percent of a vesicle forming lipid derivatized with { TAIL ~ a hydrophilic polymer }
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL