NTSR1 and cancer: Despite their abundant presence in cancer cells, suggesting them as useful drug targets, approaches to suppress EGFR- or NTR1-mediated signal transduction pathways by use of anti-EGFR monoclonal antibodies, such as cetuximab, small molecule tyrosine kinase inhibitors like erlotinib or the nonpeptide NTR1 antagonist SR 48692, have not met expectations in clinical studies so far [7].