Fig. 1

Viability of therapy sensitive and resistant variants in the presence of TKIs. a SKBR3 therapy sensitive cells, and variant resistant to 0.1 μM lapatinib, b SKBR3 therapy sensitive and variants resistant to 0.1 gefitinib or 0.5 μM gefitinib, were subjected to a MTT cell viability assay to determine the IC₅₀ by exposing the cells to different concentrations of TKIs gefitinib and lapatinib. % Cell viability in response to gefitinib or lapatinib is shown for the therapy sensitive and resistant variants. N = 4 ± SEM