Fig. 4

Comparison of membranous, cytoplasmic, and nuclear DDR1 expressions in tumor areas relative to those in corresponding adjacent benign tissue as a function of low and high GS. DDR1 immunostaining in membrane (A), nucleus (B) and cytoplasm (C) of tumor areas corresponding to low (≤ 7 [3 + 4]) and high (≥ 7 [4 + 3]) GS score. Relative DDR1 was categorized as equal expression (cancerous OSP = adjacent benign OSP), higher expression (cancerous OSP > adjacent benign OSP), and lower expression (cancerous OSP < adjacent benign OSP). Statistical comparisons were made using Fisher’s exact test. p values lower than 0.05 denote statistically significant differences