A, Immunohistochemical detection of protein expression in mice fed control diet or CDDO-Me in diet (50 mg/kg diet). Tumors were resected, fixed, and embedded in paraffin. Tissue sections were prepared for immunohistochemical staining and probed with appropriate antibodies (n = 4 per group; representative images are shown). B, Tumor tissue lysates from each group were immunoblotted with antibodies against pErbB2, ErbB2, cyclin D1, γH2AX and β-actin and quantified by densitometry. Bar represents mean ± SD of 6 tumors per group.