Venn diagram of unique and shared miRNAs down-regulated in gastric or nodal DLBCL or both. The miRNAs differentially down-regulated in high- compared with low-grade gastric lymphoma (as assessed by microarray analysis; Figure 1) were compared with the miRNAs differentially down-regulated in aggressive compared with indolent nodal lymphoma (as assessed by 454 deep sequencing). A total of 745 miRNAs were detected in the microarray/gastric lymphoma study; 57 of these were significantly down-regulated in gastric DLBCL by > 1.5-fold compared with MALT lymphoma. A total of 298 miRNAs were detected in the deep-sequencing/nodal lymphoma study, of which 87 were down-regulated by > 1.8-fold in the aggressive nodal lymphomas compared with their indolent counterparts. Forty-two down-regulated miRNAs (*P < .001 as assessed by Fisher exact test) were found to be shared between gastric and nodal DLBCL cases compared with the respective indolent disease counterparts. miRNAs known to be repressed by Myc are highlighted in red.