BCL2 and leukemia: Park et al concluded that esculetin inhibited the proliferation of human leukemia U937 cells via mitochondrial‐mediated apoptosis induction by increasing Cytochrome c release and phosphorylation of extracellular‐regulated kinase (ERK) and c‐Jun N‐terminal kinase (JNK) while simultaneously downregulating the anti‐apoptotic protein Bcl‐2.65