CASP3 and myeloid leukemia: Tatridin A is a germacranolide-type sesquiterpene lactone previously reported to induce apoptosis in human myeloid leukemia cell lines HL-60 and U937, mediated by early cytochrome c release, caspase-3 activation, and poly (ADP-ribose) polymerase-1 (PARP-1) cleavage [24].