CD33 and colorectal cancer: Recent study shows that CD14+HLA−DR−/low or CD14−CD15+CD11b+ MDSCs were negatively associated with overall survival in the retrospective analysis of renal cancer patients 45]; therefore, more works are needed to elucidate the clinical relevance of Lin−/lowHLA-DR−CD11b+CD33+ MDSCs in colorectal cancer, which may lay a theoretical foundation for MDSC-targeting therapies in this type of cancer.