CD33 and cancer: Previous studies have described significantly elevated levels of circulating Lin−/lowHLA-DR−CD11b+CD33+ MDSCs in the peripheral blood of patients with advanced cancer of multiple types, including colon cancer 27]; therefore in our study, we analyzed the presence and dynamic evolution of Lin−/lowHLA-DR−CD11b+CD33+ MDSCs in the freshly obtained whole blood from colorectal cancer with varying stage (Table 1 for demographics).