Malignant mesothelioma cells can secrete tiny vesicles containing a variety of proteins that educate the tumor microenvironment and lead to disease progression. In a recent study published online on September 8, 2016 in Scientific Reports, researchers identified the proteins that are commonly secreted inside these vesicles, which are called exosomes. The study, “Secreted Primary Human Malignant Mesothelioma Exosome Signature Reflects Oncogenic Cargo,” developed at La Trobe Institute for Molecular Science, in Australia, may provide a new source of much-needed diagnostic markers for mesothelioma, as well as new targets for future therapeutic approaches. Patients with malignant mesothelioma (MM) are often identified at an advanced stage, in part because the disease is difficult to diagnose, two points that lead to poor outcomes. Researchers believe that improved surveillance and early disease detection with MM-specific markers may improve clinical intervention and patients’ survival. To date, several blood-based biomarkers have been studied for the diagnosis of MM, but they have limited specificity, and require validation with other diagnostic methods. Researchers led by David W. Greening, Ph.D., studied the exosomes secreted by the tumor cells. These nano-vesicles contain a specific composition of proteins, lipids, mRNA, and DNA cargo components that may influence changes in surrounding cells, inducing cancer progression. In addition, exosomes from specific cells have already been used as vaccines, immune therapy, or drug delivery, which make them a valuable therapeutic tool. But to use exosomes as diagnostic or therapeutic tools, it is crucial to understand which molecules these vesicle contain, and how they affect the surrounding cells.