Myeloid-derived suppressor cells (MDSCs) are a type of undifferentiated and mature HLA-DR−CD11b+CD33+ cells [9–11] with immunosuppressive functions that play an important role in maintaining the body’s tolerance and regulating the immune response level, and they can mediate the immune escape of tumour cells, which is the main obstacle in tumour immunotherapy [12–13]. Here, CD33 is linked to neoplasm.