器官移植长期存活受者主要死亡原因之一为移植术后新发恶性肿瘤。由于受者移植术后需长期接受免疫抑制治疗，使得其机体免疫力严重下降及内环境紊乱，最终导致受者肿瘤发生风险大大增加。近年来，如何解决器官移植受者术后免疫抑制治疗与降低肿瘤发生率之间的矛盾问题正引起越来越多学者的关注。有研究证实，在器官移植受者移植器官和新发肿瘤病灶内大量蓄积髓源性抑制细胞(MDSC)，这些MDSC会诱导局部树突细胞形成耐受性树突细胞。但目前关于上述过程的具体机制还不清楚。本文就MDSC在器官移植术后肿瘤发生中的研究进展进行综述。

De novo malignant tumour will be one of the first dead reason of the long term survival transplantation patients. The depression of immune system of the transplanted recipients and abnormality of internal environment due to the acception of therapy of the immunosuppressive agents, which resulting in the tumorigenesis. The immunity reaction is contradict between the transplantation and cancer in post transplant condition. This topic has been paid close attention recently. Pioneer studies show that myeloid derived suppressor cell (MDSC) accumulated in the allografts of tolerant recipients and tissue of tumor, in where MDSC induced dendritic cells to be the tolerogenic dendritic cells. It is unknow about the mechanism of action. In this review, we try to summarize some aspects of the study progression and the role of MDSC in post transplant cancer.