PRG4 and melanoma: A ROC-AUC analysis of these two markers was performed, using the raw proteomic data, and both APOC4 and PRG4 were found to have satisfactory AUCs (Fig. 3D), and both displayed significantly higher intensities in the melanoma patient EVs in comparison to controls (PRG4: W = 390, p < 0.001; APOC4: W = 498, p < 0.001, Mann-Whitney U test; Fig. 3E).