Although there was no significant difference in frequency of CD163+ cells in CD11b+CD14+HLA-DRhi monocytes in the circulation of HNSCC patients tested overall (n = 29) pre- and post-cetuximab treatment, we observed a significant decrease in percentage of CD163+ cells in circulating CD11b+CD14+HLA-DRhi monocytes in the cetuximab clinical responders (n = 9, p = 0.049) (Fig. 3a and b). This evidence concerns the gene CD163 and head and neck squamous cell carcinoma.