If you go to Jason W. Chin's website you can see that his research involves a synthetic genetic code. So yesterday was published a paper on Nature's website where Chin's group made a ribosome capable of reading quadruplet-codons, which means an expansion of the three letters genetic code with 64 possible codons, to a four letters genetic code with 256 possibilities.

This expansion on the genetic code could pave the way to new combinations between the natural and unnatural aminoacids, toward the creation of synthetically designed proteins.