Among the 403 patients assessed for FLT3-ITD status at the initial AML diagnosis, 395 (98%) were FLT3-ITD positive, and 8 patients who were FLT3-ITD negative initially subsequently tested positive at first R/R episode (one additional patient was not tested at diagnosis, but was FLT3-ITD positive at first R/R episode). This evidence concerns the gene FLT3 and acute myeloid leukemia.