CASP8 and cancer: Casado-Zapico et al. (2011) performed an extensive study on lymphoma, acute lymphoid leukemia, and chronic and acute myeloid leukemia. The results confirmed the increase in melatonin-dependent apoptosis in the examined cancers, showing a pronounced rise of caspase 8 and of the proapoptotic protein Bid. Furthermore, the extrinsic apoptotic pathway was involved due to the augmented expression of both Fas and its ligand FasL (Casado-Zapico et al., 2011; Bizzarri et al., 2013).