Low FLNa expression levels are correlated with breast cancer progression. (A) FLNa expression levels were examined by blinded pathology analysis of TMA (n = 222 samples) from breast cancer patients with progressive disease: benign, in situ carcinoma, and invasive carcinoma. Histogram represents normalized mean of epithelial expression of FLNa levels (confidence intervals [CI] of 95% ± SEM) using a monoclonal antibody that recognizes the FLNa N terminus. Images below the histogram correspond to representative immunostaining of breast cancer tissue cores from progressive breast cancers. Differences among the three groups were compared with one-way analysis of variance and the post-hoc Tukey honestly significant difference test for multiple comparisons (*, P < 0.005). (B) An independent TMA was assembled from a total of 258 lymph node (LN)–positive and –negative breast cancer patients’ samples. Histogram shown represents normalized mean of epithelial expression of FLNa (confidence intervals of 95% ± SEM) as determined by quantitative evaluation of immunostaining. A significant decrease of FLNa expression was observed in lymph node–positive (n = 127) versus lymph node–negative breast cancer (n = 155; *, P = 0.008).