Moreover, when encapsulated in PEGylated liposomes (PL-PEP) to improve serum half-life and tumor targeting, the PL-PEP inhibited growth of mouse-borne xenografts of two human tumors, H-69, a small cell lung cancer, and DU145, a castrate resistant prostate tumor; both lack RB and harbor a mutant p53. Here, TP53 is linked to neoplasm.