Western blot analyses showing consistency between protein and mRNA expression levels in breast tumors. Equal amounts of protein (40 μg) from 6 tumor tissues were loaded. β-actin was used as loading control. For Fra-1 and Jun-D, two bands with apparent molecular weights of approximately 40 and 42 KDa, and approximately 38 and 40 KDa were observed, respectively. Figures 4A and 4D show the Western blot analysis for Fra-1, Fra-2, Jun-B and Jun-D, respectively. The results of protein expression levels were compared with the corresponding mRNA expression levels showing good correlation between mRNA and protein expression levels for Fra-1 (R2 = 0.95), Fra-2 (R2 = 0.74), Jun-B (R2 = 0.74) and Jun-D (R2 = 0.77). Figure 4B,C,E and F show correlations between mRNA and protein expression levels for Fra-1, Fra-2, Jun-B and Jun-D, respectively.