The invention provides nucleic acids, peptides, and antibodies for use in applications including diagnosis and therapy. The peptides target lung cancer and were identified by phage display. Targeting phage PC5-2 and synthetic peptide SP5-2 were both able to recognize human pulmonary tumor specimens from lung cancer patients. In SCID mice bearing NSCLC xenografts, the targeting phage was able to target tumor masses specifically. When the peptide was coupled to liposomes containing the anti-cancer drugs vinorelbine or doxorubicin, the efficacy of these drugs against human lung cancer xenografts was improved, the survival rate increased, and the drug toxicity was reduced.