On comparing gene expression in residual cancer cells, eight genes (S100A9, S100A7, CHI3L1, SLPI, SERPINA3, CASP14, URI1, and AZGP1) were found to be significantly upregulated, and 17 (ACTA2, IGFBP4, BGN, TPM2, MYLK, MMP7, HLA-DPB1, CRISPLD1, COL1A2, OLFM4, KRT14, HLA-DPA1, COL1A1, COL3A1, IFI6, IFI27, and A2M) were significantly downregulated in patients with recurrence. This evidence concerns the gene S100A9 and cancer.