Incubation with binding peptide. (A) IL-6, (B) VEGF, and (C) IGF-1 secretion measured by ELISA when the MRC5 cells or MM cells are incubated with JAG2- and Jagged-1–binding peptides. (D) IL-6 secretion measured by ELISA with MRC5 cells cultured alone, MRC5 cells cocultured with K620 (MM) cells alone, or with incremental amounts of anti–NOTCH-1 mAb (5, 10, 15, 20, 40 μg). The IL-6 secretion is inversely proportional to the amount of mAb used. Error bars represent standard deviation.