Several studies have reported the wide application of ddPCR for tracing tumor-specific mutations in AML for early detection of relapse, including NPM1, IDH1, IDH2, FLT3-TKD, NRAS, JAK2, SRSF2, SF3B1, KIT and other mutations [38,39,40,41,42]. The gene discussed is JAK2; the disease is acute myeloid leukemia.