One of the earliest demonstrations of mtPs serving as biomarkers within cancer-derived exosomes was reported by Jang et al. [2], who isolated EVs from metastatic melanoma tissues and identified mitochondrial inner membrane proteins such as MT-CO2, COX6c, and the transporter SLC25A22, showing their enrichment relative to healthy controls and their diagnostic potential in multiple tumor types. This evidence concerns the gene COX6C and neoplasm.