Figure 4. Regorafenib (REGO) increased expression of radiation (RT)-induced apoptotic proteins. A: Immunohistochemistry staining images and B: quantification of cleaved caspase-3, -8 and -9, Fas cell surface death receptor (FAS), and Fas ligand (FAS-L) expression in tumor from each group of mice are displayed. CTRL: Control, 0.1% dimethyl sulfoxide; COMB: combination therapy. Significantly different at: a¹: p<0.05, and a²: p<0.01 vs. control group (0.1% dimethyl sulfoxide; CTRL); b²: p<0.01 vs. single treatment group. Scale bar: 100 μm.