CD123 is the alpha subunit of the interleukin-3 receptor, and its expression on LSC (78% of AMLs, especially FLT3-ITDmut AML) and in R/R AMLs, as well as the low expression by normal hematopoietic progenitors, makes it an ideal target for immunotherapy. The gene discussed is FLT3; the disease is acute myeloid leukemia.