Optimized clinical performance of growth hormone with an expanded genetic code

I thought this paper was pretty interesting... This paper describes the incorporation of an unnatural amino acid into human growth hormone. This incorporation allows for a PEG group to be site specifically attached to the HGH. The PEG group improves efficacy and potency and is as safe as normal HGH. Baseball players though probably want something that is potent and out of the system quick... Either way this pretty interesting application of UAA mutagenesis!