Apoptosis inducers are chemicals or cancer fighting drugs that can be used in cellular or animal models to trigger the onset of apoptosis. The intrinsic pathway occurs in response to internal events or non-receptor-mediated stimuli, producing intracellular signals that act directly on targets within the cell and are mitochondrial-initiated events. The extrinsic pathway requires external factors often originating from the immune system that will trigger apoptosis with the involvement of transmembrane receptor such as the tumor necrosis factor (TNF) receptor superfamily. The intrinsic and the extrinsic signaling pathways converge in a single pathway called terminal, or execution pathway where cascades of proteolytic cleavage of key proteins and enzymes, including caspase 3 and poly(ADP-ribose) polymerase (PARP) result in phosphatidyl-serine (PS) exposure, DNA fragmentation and ultimately cell death under the execution pathway. Trevigen offers etoposide and staurosporine as a complement to our apoptosis line of products.