To verify whether the peptides could compete with native CBM sequences bound to NOT9 we used the fluorescently labelled NIP-WT-F as a tracer in a competitive FP experiment. Increasing concentrations of unlabeled peptides were added and their IC50 values measured as reported in figure and supplemental figure S8. These results demonstrated that all stapled peptides were weak inhibitors except for NIP-2-Ac which could compete with NIP-WT-F to the same degree as the unlabeled NIP-WT-Ac itself.