S100A9 and head and neck squamous cell carcinoma: In contrast, genes downregulated in HNSCC were associated with cellular development and differentiation (Figure 1C) and showed strong positive correlations (ρ ≥ 0.30, p < 0.05, Spearman correlation) with S100A8 and S100A9 expression as indicated by the vertical gray bars (Figure 1A and 1C; Table S2).