APP and neoplasm: However, a review of the literature showed that all of these proteins were previously identified in a secretory form: destrin (DSTN), tripeptidyl-peptidase 1 (TPP1), and amyloid beta protein (APP) in MSC-derived extracellular vesicles (EVs)66; cadherin 11 (CDH11) in tumor-derived EVs,67 cathepsin V in secretory lysosomes,68 and tyrosyl-tRNA synthetase (YARS1) as a soluble cytokine.69 This demonstrates the value of dynamic labeling in studying cell secretomes, and especially proteins released by unconventional secretory routes.