Each normal organ and pathological condition expresses a distinct set of molecules on their vasculature. These molecular signatures have been efficiently profiled using in vivo phage display technology. Using this technology, several peptides homing specifically to tumour blood vessels, lymphatic vessels, and/or tumour cells as well as to various normal organs have been isolated. Peptides homing to specific vascular addresses have revealed novel tissue-specific biomarkers of the normal and diseased vasculature. Tumour homing peptides have been successfully used to target therapies and imaging agents to tumours. In this review, we describe experimental setup for a combined ex vivo and in vivo screening procedure to select peptides homing to tumours.
