Data, pooled over three experiments, were analyzed using a generalized linear model with binomial distribution and a logit link. The relative proportions, together with 95% confidence intervals, are shown. The individual measurements are presented in Table S4. There is no significant difference in relative proportion over proteins (likelihood ratio test, P = 0.38). In addition, we performed Fischer exact test for NXF1, UPF2, and UPF3 separately with pooled data for the three experiments to test the hypothesis that the percentage labeled BR mRNPs was the same in the interchromatin and docked at the NPCs. The hypothesis was rejected: NXF1, P < 0.0001; UPF2, P = 0.008; UPF3, P < 0.0001.