A brief CNF1 exposure is sufficient to stop cell proliferation. (A) Percentage of living GL261 cells after different time periods of CNF1 exposure. Data are normalized to the values obtained in vehicle-treated control (Ctrl) cells. (B) Crystal violet staining showing multinucleation of GL261 cells after 16 hours CNF1 exposure. Scale bar = 4 μm (C) Relative percentage of multinucleated cells in dishes treated with vehicle (Ctrl) and CNF1 for different periods. All data represent means ± SEM (n = 3).