CASP3 and leukemia: In addition to squalene, tocotrienol demonstrates the strongest inhibitory effect on cellular proliferation and is linked to the activation of caspase-3, -6, and -7, in addition to causing G1, G2/M, and sub-G1 cell cycle arrest and inter-nucleosomal DNA fragmentation, which are associated with apoptosis in leukemia cells, by depleting intracellular squalene [66].