Transcytosis across the blood-brain barrier (BBB) regulates key processes of the brain. but the intracellular sorting mechanisms that determine successful receptor-mediated transcytosis in brain endothelial cells (BECs) remain unidentified. Here. we used Transferrin receptor-based Brain Shuttle constructs to investigate intracellular transport in BECs. https://www.jalyttlers.shop/product-category/heart-dish/