Western blot for inhibition of cellular neddylation and increased levels of substrates at 48 hours by DMSO, MLN4924 (positive control, 1 μM, single dose at T = 0), and compound 67 (indicated concentration, dosing at T = 0, and T = 24 hr). A) Dose-dependent inhibition of steady-state levels of CUL1 and CUL3 neddylation. B) Dose-dependent effects of 67 on steady-state levels of NRF2 and p27.