The covalently bound drug is then transported to the tumor tissue, where it accumulates via two mechanisms: 1) cancer cells have been demonstrated to use albumin as an amino acid source and, thus, show an increased uptake of this plasma protein15,16, and 2) the enhanced permeability and retention (EPR) effect, which enables macromolecules to enrich in cancerous tissue, due to disordered and thus fenestrated vascularization and impaired lymphatic drainage17. Here, ALB is linked to cancer.