Effect of DDR1 suppression by siRNA. (A) Western blot analysis for DDR1 and actin in the presence or absence of DDR1 siRNA or mutated DDR1 siRNA. (B) Flow cytometry analysis of apoptotic cells in the presence or absence of DDR1 siRNA or mutated DDR1 siRNA. The x-axis indicates annexin V–positive cells, and the y-axis indicates 7AAD-positive cells. (C) Comparison of annexin V–positive cells in the presence or absence of DDR1 siRNA or mutated DDR1 siRNA *P < .01 as compared with no stimulation, Bonferroni-Dunn test with 1-way factorial ANOVA). (D) Comparison of GM-CSF production from eosinophils of CSS patients in the presence or absence of DDR1 siRNA (**P < .01 as compared with no stimulation, Bonferroni-Dunn test with 1-way factorial ANOVA). Error bars indicate standard deviation.