近年来人们一直在积极寻找肿瘤的特异性抗原,然而欲得一理想抗原则并非易事。事实上,即使我们未能在正常细胞上检测到抗原,也不能否认肿瘤特异性抗原的存在。另一方面,某种正常抗原量的增加可能比某一新抗原的发现更为重要。正常抗原量的异常的确可反映出正常细胞与肿瘤细胞(肿瘤相关抗原)之间的差异。肿瘤抗原的产生可以是内源性的,亦可是外源性的。内源性抗原是一种正常基因异常表达的产物,这一类型包括某些癌胚抗 In recent years, people have been actively looking for cancer-specific antigens, however, the ideal anti-antigen is not easy. In fact, we can not deny the existence of tumor-specific antigens even though we failed to detect antigens on normal cells. On the other hand, an increase in the amount of some normal antigen may be more important than the discovery of a new antigen. The abnormality of the normal antigen amount indeed reflects the difference between normal cells and tumor cells (tumor-associated antigens). Tumor antigens can be produced either endogenously or exogenously. Endogenous antigen is a product of abnormal expression of normal genes, this type includes some carcinoembryonic