Recombinant human FLT3 (HZ-1151) Ligand stimulates dose-dependent proliferation of the human acute myeloid leukemia cell line (OCI-AML5). Viable cell number was quantitatively assessed by PrestoBlue® Cell Viability Reagent. OCI-AML5 cells were treated with increasing concentrations of recombinant human FLT3 Ligand for 72 hours. The EC50 was determined using a 4- parameter non-linear regression model. The EC50 values range is 0.4-3 ng/mL.