HBEGF and cancer: Cancers that exhibit HER-dependent growth have also been reported to release exosomes that display EGFR ligands, including amphiregulin [107], TGF-α [107], heparin-binding EGF-like growth factor (HB-EGF)[107], EGFR [108] and the truncated and constitutively active form of EGFR, variant III (EGFRvIII), which causes unregulated growth of cancer cells [104].