*2.5. Cell Cytometry*

After the endocytosis assay, tracer uptake was measured on a BD Accuri C6 flow cytometer (Becton Dickinson Bioscience, BDB, San José, CA, USA), counting 10,000 events at the FL2 channel. The data were analyzed by the BD Accuri C6 software. This analysis was performed in three independent experiments.
