Amazing. For GFAJ-1 to integrated arsenic into its biochemistry and eliminated the need for phosphorus to create a cell membrane or its DNA and RNA has been, until today, unprecedented. GFAJ-1 has replaced phosphorus in its biochemistry with arsenic, until now thought to be a natural poison to life here on earth. GFAJ-1 shares none of the vulnerabilities to arsenic that most life on this planet have in common. What other abnormalities are present in this completely new biochemistry? What new compounds can be synthesized from GFAJ-1’s unique genetic code? This is simply astounding!

http://www.nasa.gov/topics/universe/features/astrobiology_toxic_chemical.html