Tissue distributions of Leu-2+ cells in the spleen and draining lymph-nodes in cases of clinical gastric cancer were investigated, with special reference to suppressor cell function. Significantly higher Concanavalin-A (Con-A) induced suppressor cell activities were evident in spleen cells (SCs), as compared with peripheral blood lymphocytes (PBLs). As for the tissue distribution, the proportion of Leu-2+ (cytotoxic/suppressor) cells within Leu-1+ cells was higher in the spleen than in the lymph-nodes without metastasis. On the other hand, in lymph-nodes with metastasis, the enhanced spontaneous suppressor cell activity was noted. In addition, the proportion of Leu-2+ cells within Leu-1+ cells was the greatest in the lymph-nodes with metastasis, among the lymphoid organs tested. In lymph-nodes without metastasis, lower suppressor cell activities were noted, and numerous Leu-3+ (helper/inducer) cells were present, while Leu-2+ cells were less frequent. NK cell activity against K-562 cells was enhanced by elimination of Leu-2+/OKT-8+ cells with complement-mediated lysis. These results suggest that Leu-2+ cells located in the spleen and lymph-nodes with metastasis may predominantly act as suppressor cells and interact with effector cells.