Any change of the enzymatic cascade of NEDD8‐activating enzyme E1 and NEDD8‐conjugating enzyme E2s would cause profound influence on the neddylation status of downstream substrate proteins.[23, 32] This biological role of NNMT on neddylation pathway activation was partly reflected on the fact that in breast cancer cells NNMT promotes cell‐cycle progression by reinforcing neddylation‐mediated degradation of p27. This evidence concerns the gene NNMT and breast cancer.