Prevalence of FGFR2 in human gastric tumors and its contribution to cellular proliferation. (a) Sporadic gastric cancer samples were evaluated by quantitative digital PCR to determine FGFR2 genomic copy number. Black dots represent diffuse gastric cancers. Red dots indicate the intestinal subtype of gastric cancer. (b) Genetic characteristics of the AGS (FGFR2 diploid) and KatoIII (FGFR2 amplified) gastric cancer cell lines are shown. (c) Percent survival for the AGS cancer cell line is shown with FGFR2 inhibitors of varying specificity. (d) The KatoIII diffuse gastric cancer cell line was treated with FGFR2 inhibitors of varying specificity. The Y-axis depicts percent survival versus the X-axis with log concentrations. In all panels, error bars represent standard error of the mean. The difference in percent cell survival between KatoIII and AGS cells was statistically significant (P <0.05) at the three highest concentrations of all drugs, except Brivanib which was only significant at the highest concentration.