The molecular analysis of these variants allowed the design of optimised assays for the diagnosis of the API2-MALT1 gene rearrangement..     ///    Heterogeneity of the API2-MALT1 gene rearrangement in MALT-type lymphoma..     ///    RT-PCR analysis and DNA sequencing demonstrated the expression of an API2-MALT1 fusion transcript in 18/24 gastral and extragastral MALT-type lymphomas. 