Before revision: The enhanced permeability and retention (EPR) effect is a controversial concept by which molecules of certain sizes (typically liposomes, nanoparticles, and macromolecular drugs) tend to accumulate in tumor tissue much more than they do in normal tissues.
After revision: 280px| Enhanced permeability and retention (EPR) effect and passive targetingThe enhanced permeability and retention (EPR) effect is a controversial concept by which molecules of certain sizes (typically liposomes, nanoparticles, and macromolecular drugs) tend to accumulate in tumor tissue much more than they do in normal tissues.