TNF and colitis: In addition to this, early in vitro work by Okamoto et al. suggests siRNA containing liposomes targeted to heparin-binding epidermal growth factor (HB-EGF) using anti-HB-EGF Fab′ fragments could provide effective treatment for breast cancer.83 Similarly, Laroui et al. demonstrated effective treatment of colitis through the delivery of TNF-α siRNA encapsulated within F4/80 Fab′ targeted PEG–PLA polymersomes.84 The group found that Fab′ targeted TNF-α siRNA containing nanoparticles granted a greater reduction in all symptoms of colonic inflammation when compared to the non-targeted controls.