Claudin-low cell lines express higher transcript and protein levels of GLI1 . (A) Expression of CD44, CD24, CDH1, GLI, and CLDN3, 4, and 7, transcripts across a panel of breast cancer cell lines . Multiple probes for each gene were extracted from microarray data and their expression values were Z transformed and plotted as a heat map. BaA = basal A, BaB = basal B, Lu = luminal. Asterisks denote cell lines originally identified as claudin-low . Yellow box surrounds the expression of Gli family members in claudin-low cell lines. (B) Graph of relative Gli family expression levels in claudin-low (I) and EMT (II) cell lines, relative to controls. Error bars represent standard error, and n.s. indicates that no signal was achieved under the parameters used. (C) Immunoblot of GLI1 levels in the indicated claudin-low cell lines. GAPDH serves as a loading control. (D) Plot of GLI1 expression data from UNC337 mammary tumor and tissue dataset, based on subtype. 99% confidence interval is shown, with outliers plotted as single data points. Significance was calculated using one-way ANOVA using multiple comparisons, and all significant comparisons between the claudin low data set and others are indicated. ** = P ≤0.005. ANOVA, analysis of variance; EMT, epithelial-to-mesenchymal transition; GAPDH, glyceraldehyde phosphate dehydrogenase; GLI1, glioma-associated oncogene 1.