C. Quantification of Sec24C membrane association after CDK inhibitor treatment. Digitonin-permeabilized cells treated with vehicle (CTRL) or the indicated CDK inhibitor (1 µM, 3 h) were immunostained for Sec24C. The mean intensity of Sec24C in the perinuclear area normalized for the cytosolic Sec24C signal in drug-treated cells is expressed as fold change compared to the control; n= 60-80; mean ± s.e.m. of three independent experiments ****p<0.0001, One-way ANOVA with Dunnett's multiple comparison test. 