Fig. 1

S100A16 protein was progressively down-regulated from NHOM to ODL and OSCC and low S100A16 protein expression correlated with poor OSCC prognosis. a Representative NHOM specimen showed strong, predominantly membranous S100A16 expression in the epithelial compartment. Basal cell layer (arrowheads), however, was mostly negative for S100A16 expression (A1). b Expression pattern of S100A16 in ODL was similar to that of NHOM. However, the expression intensity was weaker than that in NHOM (c) Representative OSCC lesion showing a gradient of S100A16 expression: central area (C1) showed a strong, membranous staining in contrast to a very weak, mostly cytoplasmic staining in the invading front area (C2). d Graphic illustration of S100A16 PLI score demonstrated gradual down-regulation of S100A16 from NHOM to ODL, OSCC and positive cervical nodes. ANOVA test with Bonferroni Post-Hoc was used for the statistical analysis. P-value: ***, <0.001; ns, not significant. e Kaplan-Meier curves showing reduced 10-year survival probabilities for patients with low S100A16 PLI score. Log-Rank test was used for statistical analysis