Urinary exosomes may be useful as treatment response markers in prostate cancer. Exosomes secreted from tumour cells can deliver signals to surrounding cells and have been shown to regulate myofibroblast differentiation. In melanoma, tumor-derived vesicles can enter lymphatics and interact with subcapsular sinus macrophages and B cells in lymph nodes. A recent investigation showed that exosome release positively correlates with the invasiveness of ovarian cancer. Exosomes released from tumors into the blood may also have diagnostic potential. Exosomes are remarkably stable in bodily fluids strengthening their utility as reservoirs for disease biomarkers. Patient blood samples stored in biorepositories can be used for biomarker analysis as colorectal cancer cell-derived exosomes spiked into blood plasma could be recovered after 90 days of storage at various temperatures.