LTF and brain neoplasm: Because of its ability to cross the BBB through LfR-mediated transcytosis processes within brain capillary endothelial cells [44,56] and its relatively good biocompatibility, safety, stability and resistance to proteolysis [5], the use of exogenous Lf as a therapeutic agent or the use of drug-loaded Lf-based nanoparticles were explored for the treatment of neurodegenerative diseases, cerebrovascular diseases, childhood developmental delays, brain tumors and other neurological-related diseases [57,172,173].