R-RAS2 protein expression in human CNS tumors. Samples were obtained from the commercial Brain Tumor Screen tissue microarray (CC17-11-004). Cryostat sections of human brain tissue (from normal brain, hyperplasias, glioblastoma grade III or IV, astrocytoma grades I, II or III, and oligodendroglioma grades I, II or III) were analyzed by immunostaining with antibodies against R-RAS2, and they were counterstained with hematoxylin and eosin. A quantitative analysis of R-RAS2 expression was performed for each brain tumor subtype, normalizing the R-RAS2 values to the levels expressed in normal tissue. R-RAS2 protein expression is represented as the diaminobenzidine absorbance, which reflects the presence of the protein in the samples. Student’s t-test *p < 0.05, **p < 0.0005, ***p < 0.00005. ANOVA p < 0.00001. Scale bars = 50 μm.