CD19 and acute myeloid leukemia: The initial AML blasts in the MRD gate (CD19-, CD45+, CD3-, CD38+/CD34±, CD7+/CD117+, CD117+/CD135+) were detectable at the lowest frequency in our current study at 22 cells per 100,000 (0.022%) CD45+CD3- living singlet parental population.