“…A more in-depth analysis of Figure 2 shows the presence of changes in the spectral shape and in the relative intensity of several absorption bands, namely the carbohydrates and nucleic acids band at 1000–1200 cm −1 [ 16 , 19 ], the protein Amide I and II bands [ 13 , 36 , 37 ], the lipid C-H stretching band at 2800–3000 cm −1 [ 23 , 38 ], and the C=O stretching at approximately 1735 cm −1 , which has been assigned to purine base and ester groups of lipids in EV samples [ 9 , 36 , 37 ]. These bands are highlighted in green and red color in controls and patients, respectively, and are considered a major source of spectral biomarkers in EV research [ 4 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 23 ]. To investigate more in-depth the difference between the two groups, an enlarged detail of the four mentioned IR bands for controls (green) and oncologic patients (red) is reported in Figure 3 .…”