Gadd45A expression levels in human breast cancer samples are dependent on the hormone receptor subtype. (A) Box and Whisker Plots graphically depict the expression pattern of Gadd45a in the subtypes of human breast cancer. There was a highly significant difference in percent Gadd45a staining between groups: Normal 16.3%; Luminal A 65.3%; Luminal B 85.7%; HER2+ 40.5%; TN 31.2%, P < 0.001, ANOVA. (B) Representative images from immunohistochemical analysis of Gadd45a of Normal (a), Luminal A (b), Luminal B (c), Her2+ (d) and Triple Negative (e) breast tissue. Immunostaining was reviewed and scored by three independent observes. Percent positive stainings for each specimen were averaged and categorized as: Negative (0- < 10%, Neg), Low (10–<40%), Medium (40–<70%, Med), or High (≥70%).