COL1A2 and neoplasm: As shown in Fig. 2a, b, there was no significant correlation between COL1A1 mRNA expression and clinicopathological parameters regarding age, gender, depth of invasion, tumor size, degree of differentiation, and lymph node status (all p > 0.05), while no significant difference of COL1A2 expression was observed regarding gender, age, degree of differentiation, and lymph node metastasis (Fig. 2c, d), but COL1A2 expression was higher in the advanced stage and larger tumor size (p = 0.016 and p = 0.0385, respectively) (Fig. 2d).