To identify RTKs whose activation desensitizes tumor cells to AZD4547, SNU16 and KATOIII cells were treated with AZD4547 (0-10 nM) alone or accompanied by five simultaneous treatments with different ligands, including hepatocyte growth factor (HGF), epidermal growth factor (EGF), platelet-derived growth factor (PDGF), neuregulin 1 (NRG1) and insulin-like growth factor (IGF) (50 ng/mL) for 72 hours. The gene discussed is EGF; the disease is neoplasm.