56 The Dream of Elixir Vitae One specific case is the brain, the source of our consciousness. Again, the primary strategy should be to foster regeneration. It appears dangerous to use viruses and bacteria as vectors for gene therapy in the brain, so again stem cells hold the greatest promise. Non-invasive methods to express exogenous genes in the brain already exist and may serve to express specific critical genes. [38] In  addition,  several  species  such  as  reptiles,  lobsters  and birds feature advanced regenerative capacities and appear not to age. Deriving information from these species to engineer how  to  rebuild  the  human  genome  to  avoid  aging  is  also within our reach. [39] In another example, work is being con- ducted to attempt to implement the advanced regenerative capacity of amphibians to mammals. [40] Synthetic biology and information systems will be the ‘glue’ that binds all these fields together and allow us to design, regulate, and apply the Elixir. CONCLUSION Elixir Vitae needs not be anything besides present technolo- gies combined with some engineering feats. Importantly, the theoretical basis for these technologies already exists. What remains  is  the  engineering  problem  of  making  them  work according to our needs. Namely, we must (1) develop thera- pies based on stem cells for tissue regeneration; (2) implement synthetic biology to control stem cells; (3) test and develop the safety and accuracy of RNAi, gene therapy, and molecular therapies; (4) learn more about regeneration and the signals involved in each type of tissue; (5) apply whole genome engi- neering to aging. Lastly, we need to know, of course, where to act. That is, what causes aging in humans, what makes us