CNF1 induces senescence of glioma cells. (A–C) Percentage of SA β-gal positive GL261 (A), U87 (B), and GBM-derived glioma cells (C) 48 h after CNF1 treatment. Data are mean ± SEM. **P < .01 (t-test). (D, E) Representative coronal brain sections from glioma-bearing mice treated with either vehicle (D) or CNF1 (E). Note very intense SA β-gal staining (blue) in the CNF1-treated animal. For both images, the glioma mass is on the right while the intact peritumoral cortex is on the left. Scale bar = 200 µm. (F) Quantification of SA β-gal staining in vehicle- and CNF1-treated mice. The horizontal lines in the box denote the 25th, 50th, and 75th percentile values. The error bars denote the 5th and 95th percentile values, and the square symbol represents the mean of the column of data. SA β-gal staining is more intense in CNF1-treated mice (Mann–Whitney rank sum test, ***P < .001).