Figure 4. Effect of imatinib on the growth of three KIT+ lung tumors and a KIT negative malignant pleural effusion (MPE).

First passage cells derived from primary patient material was incubated in the presence or absence of imatinib (5 µM) for 4 days. Top panels, photomicrographs of cultured cells. Histograms show the fold-change in cell number for specific cell subsets, defined by flow cytometry, in the absence or presence of drug. Bars show mean values. Error bars show the standard error of the mean. The p values were determined by Student's paired t-test (2-tailed). Supplementary figure S4 shows the gating strategy used to define the populations of interest.