. The mRNA levels of COL1 (A) and COL3 (B) in normal skin fibroblasts ( = 0.24, s = 0.06; = 0.28, s = 0.05, respectively) were significantly lower, compared with other three groups. However, there is no significant difference in mRNA levels of COL1 (A) and COL3 (B) in HSFBs transfected with Slug shRNA ( = 0.82, s = 0.08; = 0.78, s = 0.12, respectively), compared with non-transfected HSFBs ( = 0.95, s = 0.17; = 0.85, s = 0.08, respectively) and HSFBs transfected with control shRNA ( = 0.80, s = 0.11; = 0.92, s = 0.14, respectively), suggesting Slug shRNA had no effect on the collagen proteins synthesis in HS formation. *: P<0.01 versus Slug shRNA; †: P<0.01 versus Control shRNA; ‡: P<0.01 versus HSFBs.