Using the Oxford Nanopore cDNA platform, we generated nearly 2 billion long reads (median 25.8 million per sample) from 71 human samples, including 48 acute myeloid leukemia or myelodysplastic syndrome samples, 25 of which had splicing-factor gene mutations (in <i>SRSF2</i> , <i>U2AF1</i> , or <i>SF3B1</i> ). The gene discussed is U2AF1; the disease is acute myeloid leukemia.