CHEK1 and acute myeloid leukemia: We found that the expression of CHK1 in FLT3-ITD positive AML cases was significantly higher than that of FLT3-ITD negative AML cases (Fig. 2A), while there was no significant difference in the expression of other genotypes, including t(8;21), PML-RARa, and Inv(6) (Fig. 2B).