Figure 4. Immunohistochemical analysis of the tumor samples.
(a) Immunohistochemical staining on tumor sections: epidermal growth factor receptor (upper), prostate apoptotic response 4 (middle), and apoptosis inducing factor (AIF) (bottom). Magnification = ×200. (b) Quantitative analysis of nuclear translocation of AIF in the tumors treated with different formulations. **indicates P < 0.01, *indicates P < 0.05. NP, nanoparticle; PBS, phosphate-buffered saline; siRNA, small interfering RNA.