does not cross cell membranes), whole body vitrification might become possible. Human fibroblasts have already been induced to synthesize cryoprotectant trehalose by genes introduced using recombinant adenovirus vectors  [ NATURE BIOTECHNOLOGY; Guo,N; 18(2):168-171 (2000) ]. Cryonics is the cryopreservation of legally dead humans at cryogenic temperatures in the hope that future