MLN4924 is a selective NAE inhibitor that has been reported to be a promising anticancer drug candidate.15 In cellular and animal models of lymphoma, colorectal cancer, liver cancer, pancreatic carcinoma, bladder urothelial carcinoma and breast cancer, MLN4924 has been shown to inhibit tumor cell proliferation and metastasis.16, 17, 18, 19, 20, 21 MLN4924 has also been reported to enhance p21-dependent radio-sensitization in human breast cancer cells and suppress tumor angiogenesis.21, 22 To date, the detailed mechanisms of NEDD8 and its inhibitor MLN4924 in human NPC remains unknown. Here, NEDD8 is linked to breast cancer.