Differentiated DC markers and T cell co-stimulatory ligands were further examined on the CD33+ subset of MDSC and found to be expressed at similarly low levels between suppressive and non-suppressive CD33+ cells isolated from tumor co-cultures (p = NS) (Figure 7), suggesting that the maturation and antigen presenting defects of MDSC are not primary in T cell suppression. This evidence concerns the gene CD33 and neoplasm.