1. New Drug Discovery Research Laboratory, Kanebo Ltd., 1-5-90 Tomobuchi-Cho, Miyakojima-Ku, Osaka 534, Japan, Basic Science Laboratory, Kanebo Ltd., 5-3-28 Kotobuki-Cho, Odawara, Kanagawa 250, Japan, and Department of Molecular Immunology and Pathology, Cancer Research Institute, Kanazawa University, 13-1 Takara-machi, Kanazawa, Ishikawa 920, Japan