Abstract: Embodiments herein report compositions, systems, methods, and uses for diagnosing and/or treating a condition in a subject. In certain embodiments, one or more peptides can be used as biomarker detectors for predicting onset or progression of disease. Some embodiments of the present invention report peptides capable of associating with MVs for predicting onset or progression of cancer in a subject. Other embodiments include methods of generating and or modifying peptides of use herein. Yet other embodiments herein report biomarker detectors capable of detecting agents associated with cancer progression, for example, metastasis.