Effect of PAO on fresh AML blast colony-forming cells. After adherent cell fractionation of adherent cells and depletion of T lymphocytes, remaining cells were cultured in a clonogenic assay with PAO at concentrations ranging from 0.01 to 0.1 μmol/L. AML colonies are presented as the percentage of control (the mean number of colonies obtained in the absence of PAO). Data from patients no. 1 through 6 are depicted.