CD34 and acute myeloid leukemia: In standardized FACS assay, the CD34 positivity of promyelocytic AML-derived cells (NB4; 41.0%) and monocytic AML-derived cells [THP-1 (72.2%), Nomo-1 (18.9%), MV4-11 (40.9%), SigM5 (15.3%), and MM-1 (66.0%)] (Figure 4A) was significantly higher than minimum accepted level of 10–20% CD34 positivity for AML.