DNA mismatch repair-deficient colorectal tumors (CRC) frequently show coding microsatellite frameshift mutations in the MSI tumor driver Transforming Growth Factor Beta Receptor Type 2 (TGFBR2) leading to cellular alteration of MSI tumor cells [Lee, J., Warnken, U., Schnölzer, M., Gebert, J. & Kopitz, J. (2015) Protein Sci. 24, 1686-94; Lee, J., Ballikaya, S., Schonig, K., Ball, C. R., Glimm, H., Kopitz, J. & Gebert, J. (2013) PloS one. 8, e57074]. Whether this receptor expression in MSI tumor cells also impacts the exosomal proteomic cargo of these cells is still unknown.