EGFR and cancer: Taken together, these results suggest that in this cancer cell model of acquired resistance to three different TKIs, activation of AKT- and MAPK-driven intracellular signals may be responsible for cancer cell growth in the presence of either selective anti-EGFR TKIs, such as gefitinib or erlotinib, or in the presence of broad spectrum TKI, such as vandetanib.