(A) 1483, (B) PCI-37B, and (C) Cal-33 cells were plated in 12-well plates at a density of 3 × 104 cells/well in DMEM with 10% FBS. After 24 hours, growth media was replaced with media containing DMSO, AZD0530 (at IC50 value), gefitinib (at IC50 value), or a combination of AZD0530 and gefitinib. On days 0, 2, 4, 6 and 8, viable cells were counted using vital dye exclusion. Four independent experiments (in triplicate) were performed for each cell line. Cell numbers on day 8 after treatment are shown.