In order to assess proteasome activity in HNSCC lines we engineered UM-SCC4, UM-SCC6, UM-SCC12, UM-SCC-17B, Cal33 and FaDu cells to report the activity of this protease by accumulation of a fusion protein between the fluorescent protein ZsGreen and the C-terminal degron of murine ornithine decarboxylase (cODC). The gene discussed is ODC1; the disease is head and neck squamous cell carcinoma.