Expression and correlation of β-catenin and Mcl-1 in GIST. (A) Representative tumor (T) and normal (N) tissue samples analyzed by immunoblotting with anti-β-catenin, anti-Mcl-1, and anti-β-actin antibodies. (B) Comparison of the average β-catenin and Mcl-1 protein expression by western blotting analysis in tumor tissues (mean ± SD, 0.42 ± 0.25 and 0.80 ± 0.21, respectively, n = 31) and normal counterpart tissues (mean ± SD, 0.03 ± 0.07 and 0.36 ± 0.26, respectively, n = 16). Columns, mean; bar, SD. *, P <0.001. Equal amounts of protein loading were ensured using β-actin as the internal control. (C) There was a significantly positive correlation between β-catenin and Mcl-1 expression by Pearson correlation analysis (r = 0.660; P <0.001). (D) Representative immunohistochemical staining showing strong immunoreactivity for OPN (upper) and Mcl-1 (lower) in GIST. Original magnification, ×200.