CASP9 and myeloid leukemia: The antiproliferative effect of CA (2.5–10 μM) was also reported on HL-60 and U937 human myeloid leukemia cells attributed to inhibition of cell cycle progression with a transient blockage in the G1 phase (14), while another study with HL-60 cell reported that a high dose of CA (100 μM) induces apoptosis associated with activation of caspase-9 and -3 (26).