Figure 5.

Type I collagen expression correlated to smoking habit (A, B and C) and to site (D, E and F).
A = Mild oral epithelial dysplasia (OED) of non-smokers had a higher collagen expression than those with severe OED and moderately differentiated oral squamous cell carcinoma (OSCC) (P = 0.0065).
B = Non-smokers demonstrated fewer protein levels in high-risk and moderately differentiated OSCC (P = 0.001).
C = Mild OED in non-smokers had a higher index than high-risk, and low-risk more than severe OED (P = 0.0013).
D = Mild OED showed more collagen than well and moderately differentiated OSCC in the tongue (P = 0.0008).
E = Low-risk had more collagen than high-risk and moderately OSCC in the tongue (P = 0.0269).
F = Mild OED or low-risk lesions in the tongue showed higher expression than cases in other sites (P = 0.0033).