MALT1 and gastric mucosa-associated lymphoid tissue lymphoma: API2-MALT1 translocation is a very frequent genetic event, reported in up to 25% of patients with gastric MALT lymphoma and 35% of patients with pulmonary MALT lymphoma, but is less common at other sites.[5] The occurrence of API2-MALT1 has been associated with antibiotic resistance in HP-positive gastric MALT lymphoma.