Fig. 5

Low KLK6 expression is a risk factor for unfavorable overall and progression-free survival. Representative pictures of an IHC staining on tissue sections of normal mucosa (A) and primary HNSCC (B–C) demonstrates tumor samples with low (B) and high (C) KLK6 protein expression (brown signal). Counterstaining with hematoxylin to visualize tissue architecture; black bar = 100 μm. Association between KLK6 protein staining and overall survival (D), or progression-free survival (E) was assessed by univariate Kaplan-Meier analysis. Green line = subgroup with high KLK6 staining pattern and blue line = subgroup with low KLK6 staining pattern. Representative pictures of IHC staining (brown signal) demonstrate inverse regulation of KLK6 and Vimentin protein expression (F), or KLK6-related differences in cellular β-catenin localization (G) on serial tumor sections. Inlets represent larger magnifications to demonstrate prominent staining of β-catenin at the membrane or its nuclear accumulation. Counterstaining with hematoxylin to visualize tissue architecture; scale bar = 100 μm. T = tumor and S = stromal tissue