Immunohistochemical expression of matrix metalloproteinase-9 and 13 in oral squamous cell carcinoma and their role in predicting lymph node metastasis

Table 2 Staining and grading of matrix metalloproteinase-13

Grade	Interpretation
0	No staining of the tumor or stromal cells
1+	Mildly (< 50%) positive staining of the tumor cells and/or weak staining of stromal cells
2+	Moderately (> 50%) positive staining of the tumor cells and/or moderate staining of stromal cells
3+	Intense staining of the tumor cells and/or strong staining of stromal cells. No normal epithelial cells were stained