已有研究表明从大豆中提取的蛋白酶抑制物（ＰＩ）和皂甙有预防肿瘤的作用。本研究发现它们增加环磷酰胺（ＣＴＸ）对小鼠的抑瘤作用，又能减低对小鼠外周血细胞和骨髓有核细胞的毒性副作用，同是也发现它们对小鼠的免疫功能有促进作用。这些提取物可望作为人体肿瘤化疗的辅助用药。 Studies have shown that the protease inhibitors (PI) and saponins extracted from soybeans have a role in preventing tumors. This study found that they increase the inhibitory effect of cyclophosphamide (CTX) on mice, and can also reduce the toxic side effects on peripheral blood cells and bone marrow nucleated cells in mice. It is also found that they promote the immune function of mice. . These extracts are expected as an adjunct to chemotherapy for human cancers.