Patient 2, a 66-year-old female, had <i>KMT2A</i> amplification (8~11 copies in 87.5% of peripheral blood cells) and <i>CRLF2</i> rearrangement, representing the first reported case of <i>de novo</i> Ph-like B-ALL with <i>KMT2A</i> amplification in an adult. This evidence concerns the gene CRLF2 and acute lymphoblastic leukemia.