The anti-CD123 antibody (CD123-IgG1+) mediated the killing of blasts from about half the samples from patients (AML no. 1 to 3; Fig. 1a) but was barely active against blasts from the other half of samples (AML no. 4 to 7; Fig. 1a), therefore separating samples into two groups: CD123-IgG1+-responders and CD123-IgG1+-nonresponders. This evidence concerns the gene IL3RA and acute myeloid leukemia.