(a) Carious (i, iii, v, and vii) and healthy (ii, iv, vi, and viii) teeth stained with H&E (i and ii), anti-S100A8 (iii and iv), anti-S100A8/S100A9 (v and vi), and anti-neutrophil elastase (vii and viii). (b) Human inflamed gingiva stained with anti-S100A8. Shown are negative (omission of primary antibody and replacement with nonimmune rabbit immunoglobulin G) (i) and positive (ii) controls. Field widths: for i and ii of panel a, 479 μm; for iii to viii of panel a, 241 μm; for i and ii of panel b, 241 μm.