FLT3 and acute myeloid leukemia: Comparative Real-Time PCR analysis of 21 hematopoietic genes [31] in 2 subsets of AML cells, the N-CoR positive cells, HL-60 (a AML-M2 derived cell line) and U937 (a monocytic cell line derived from histocystic lymphoma), and the 5 AML-M5 cells namely THP-1, Nomo-1, Mono-Mac-1 (MM1), MV-4-11 and SigM5 in which N-CoR was lost, identified Flt3 as the gene selectively up-regulated in all AML-M5 cells (Fig. 1 and Fig. S1).