Cytogenetic abnormalities at chromosome 1q21 are among the most common second genetic events observed in Non-Hodgkin's Lymphomas and have prognostic significance. Recently, BCL9 has been cloned from a pre-B-cell lymphoblastic leukemia cell line, which carried a t(1;14)(q21;q32). However, among a pane] of 39 B-cell malignancies with 1q21 translocation, only two cases showed rearrangement for the BCL9 gene. We report the establishment of a new lymphoma cell line from a patient with relapsed diffuse large cell lymphoma. This cell line SKI-DLCL-1 showed cell surface antigens identical to the original tumor and demonstrated the profile of a mature B-cell phenotype: CD19 and CD20 positive, CD5 and CIO negative. It carried a t(1;14)(q21;q32) translocation identical to the original tumor. Although the clinical presentation was an isolated effusion lymphoma, studies for HIV-1, HHV8 and EBV were all negative. Southern blot analysis demonstrated that BCL9 was not rearranged in the SKI-DLCL-1 cell line. In addition, the BCL9 gene was not over-expressed in SKI-DLCL-1 cell line. The identification of a new locus at 1q21 will help clarify the pathogenesis of B-cell malignancies with a translocation involving this locus.