A box plot of serum VEGF (pg/mL), SCF (pg/mL), and soluble KIT levels (AU/mL) in 66 patients with GISTs and 40 controls. The horizontal lines indicate the 10th, 25th, 50th (median), 75th, and 90th percentiles of the variables, and values above the 90th and below the 10th percentiles are plotted as closed circles.