“parent” and cannot be regarded as a genetic firewall. The possibility of reassigning the function of large number of triplets opens the perspective to have strains that combine XNA, novel base pairs, new genetic codes, etc. that cannot exchange any information with the natural biological world. Regardless of changes leading to a semantic containment mechanism in new organisms, any novel biochemical systems still has to undergo a toxicological screening. XNA, novel proteins, etc. might represent novel toxins, or have an allergic potential that needs to be assessed. Governance and regulatory issues Xenobiology might challenge the regulatory framework, as currently laws and directives deal with genetically modified organisms and do not directly mention chemically or genomically modified organisms. Taking into account that real xenobiology organisms are not expected in the next few years, policy makers do have some time at hand to prepare themselves for an upcoming governance challenge. Since 2012, the following groups have picked up the topic as a developing governance issue: policy advisers in the US, four National Biosafety Boards in Europe, the European Molecular Biology Organisation, and the European Commission's Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) in three opinions (Definition, risk assessment methodologies and safety aspects, and risks to the environment and biodiversity related to synthetic biology and research priorities in the field of synthetic biology.). See also Auxotrophy Biological dark matter Body plan Directed evolution Expanded genetic code Foldamer Hachimoji DNA Hypothetical types of biochemistry Life definitions Nucleic acid analogue Purple Earth hypothesis RNA world Shadow biosphere References External links XB1: The First Conference on Xenobiology May 6–8, 2014. Genoa, Italy. XB2: The Second Conference on Xenobiology May 24–26, 2016. Berlin, Germany. Bioinformatics Biotechnology Emerging technologies Synthetic biology