What gets Scripps Chemistry Professor Floyd Romesberg up in the morning is understanding and evolving protein function. To this end, he is working to increase the information capacity of DNA by developing a third, artificial base pair, for eventual in vivo application in an unnatural organism that can build proteins with unnatural amino acids. In twelve short years, he and his team have been able to find new ways to replicate, first in the test tube and now in single bacterial cells, this artificial nucleotide. His success challenges us to re-examine our assumptions about nature’s design and embrace the exciting new potential of protein therapeutics.