The product of the t(11;18), an API2-MLT fusion, marks nearly half of gastric MALT type lymphomas without large cell proliferation..     ///    A genuine API2-MLT fusion transcript of variable length was demonstrated in 11 out of 58 cases.     ///    Here we report the development of an RT-PCR approach for the detection of the API2-MLT fusion transcript and its application for the analysis of 58 cases of gastric lymphoma.     ///    These observations allowed us to work out a highly sensitive diagnostic test for the API2-MLT fusion on an ABI Prism 7700 sequence detector that confirmed the results of our initial approach.     ///    The API2-MLT fusion was found in 48% of gastric marginal zone cell lymphomas of MALT type that did not contain a large cell component and it was lacking in all other lymphomas of the stomach.. 