EGFR and metastatic colorectal cancer: First, unlike antibodies, using TKIs for targeting EGFR (e.g., gefitinib or erlotinib) or VEGFR (e.g., vatalanib, sunitinib, sorafenib and cediranib) has shown disappointing results in trials of TKI combined with chemotherapy for metastatic colorectal cancer; [12], [13], [14], [23], [41], [42], [43], [44], [45], [46], [47] similarly, all phase III trials of single agent TKI have failed with the exception of one trial utilizing regorafenib in latter line therapy.