From the Molecular Pathology Program, * Centro Nacional de

Different studies have already shown that the isolated inactivation of p21, p16, or p27 cyclin-dependent ki-nase inhibitors (CKIs) is associated with increased growth fraction, tumor progression, or decreased overall survival in cases of non-Hodgkin’s lymphoma. In this study we linked molecular study of the p53 and p16 genes with immunohistochemical analysis of p27 expression in a group of aggressive B-cell lymphomas [large B-cell lymphomas (LBCLs) and Burkitt’s lym-phomas]. This was done to analyze the relationship between p53 and p16 silencing, p27 anomalous over-expression, and clinical follow-up, testing the hy-pothesis that the accumulation of CKI alterations could confer to the tumors a higher aggressivity. In a group of 62 patients, p53 inactivation as a result o