Miyazaki K, et al. - Among 11 patients (median age was 59 years) with duodenal-type follicular lymphoma (DTFL), researchers sought to analyze the m7-FLIPI score and gene mutations according to the sites of involvement. In addition to esophagogastroduodenoscopy and colonoscopy in all the patients, intestinal involvement was examined by double-balloon endoscopy and/or capsule endoscopes. Genomic DNA was investigated utilizing the AmpliSeq Comprehensive Cancer Panel examining the exonic regions of 409 genes and direct sequencing of MEF2 (exon 2 to 3). The results suggest that the m7-FLIPI model in this cohort was valid with DHFL patients. KMT2C incidence was higher than that of the other lymphoma subtypes (1-13%). Mutations of KMT2C and NOTCH2 may be associated with the diversity of DTFL intestinal involvement sites.