In spite of clinical remission, the local condition in pseudotumor and Graves' ophthalmopathy suggest active inflammatory disease.25 Proliferating cell nuclear antigen (PCNA) activity in conjunction with the ratio of B-/T-cells may be a helpful immunohistologic adjunct for differentiating purely inflammatory lesions of the orbit from lymphoid tumors. The gene discussed is PCNA; the disease is Graves ophthalmopathy.