CD33 and head and neck squamous cell carcinoma: In contrast to the mature lineages seen in medium only myeloid cells, CD33+ and CD11b+ suppressor cells isolated from PBMC after tumor co-culture (USC-HN2 or SCCL-MT1 HNSCC for CD33+, MCF7 breast or NCI-H60 small cell lung for CD11b+) showed an abundance of immature cells, including metamyelocytes or band cells and blast-like cells (middle left and far right panels, representative images shown of three independent experiments).