EGFR and neoplasm: Obviously, improving the avidity of the α-EGFR TM increases the targeting capability: While the monovalent α-EGFR TM strongly binds only to tumor cells expressing high levels of EGFR, the bivalent α-EGFR-EGFR TM is able to efficiently bind to tumor cells with high, intermediate or even low EGFR surface expression levels.