Effect of octreotide on survival of primary isolated B-B4⁺ plasma cells. Cells were seeded at 6 × 10⁵ cells/mL, incubated for 24 hours, and counted. Octreotide (10⁻⁸ mol/L), IL-6 (100 U/mL), and IGF-I (10⁻⁷ mol/L) were added as indicated. (□) Patient sample 1; () patient sample 2.