izTRAIL (soluble) (human), (re

izTRAIL is a highly active recombinant form of soluble human TRAIL. Due to a trimerizing N-terminal isoleucine zipper (iz) motif the intrinsic trimerization of TRAIL, required for apoptosis-inducing activity of TRAIL, is enhanced when compared to non-tagged soluble human TRAIL (shTRAIL). Therefore, izTRAIL is a potent inducer of apoptosis in many human cancer cells, but not normal human hepatocytes. In addition, the half-life of izTRAIL is about eight-fold higher than the half-life of shTRAIL. These properties render izTRAIL highly suitable for both, in vitro and in vivo use, particularly for studies in which investigators plan to transfer their in vitro results into an in vivo system with human cancer cells in xenotransplant settings examining susceptibility to TRAIL-induced apoptosis.