Coculture experiments with physical contact between Saos-2 cells and myeloma cells (>98% pure) from 3 patients. (1) Saos-2 cells alone, (2) myeloma cells and Saos-2 cells, (3) myeloma cells and Saos-2 cells in the presence of anti-HGF serum 1:1000, or (4) preserum 1:1000. Supernatants were harvested after 48 hours. IL-11 was measured in duplicates by ELISA and data are means ± SD.