NSCLC lines of known genetic backgrounds (Table 1) were treated with the MEK inhibitor CI-1040. Figure 2A shows that the LKB1/KRAS mutant cell lines have a uniform enhanced sensitivity to CI-1040 when compared with wild-type cell lines, LKB1 mutant lines or KRAS mutant lines (labelled control cell lines in Figure 2B)...The mean relative proliferation rate calculated for LKB1/KRAS mutant cell lines, and compared with the control cell line cluster was statistically significant (P<0.001 at all CI-1040 concentrations >0; Figure 2B). LKB1/KRAS mutant cell lines have a mean IC50 value of 5 μ M compared with the control cell lines, which have a mean IC50>10 μ M. ..