PCNA and non-Hodgkin lymphoma: Proliferating Cell Nuclear Antigen may be used as a marker of cell proliferation in clinical studies to estimate biological aggressiveness of lymphomas; its determination in intermediate grade NHL could be very useful to evaluate individual cases in this group and determine prognosis and the appropriate therapy(20,23).In the current study, the expression of P53 and PCNA in 35 biopsies of NHLs was found to increase from low to high grade tumors, suggesting that this may be of prognostic value in these disorders.