Matz, M. V., Lukyanov, K. A., and Lukyanov, S. A.
Family of the green fluorescent protein: journey to the end of the rainbow. BioEssays 24: 953-959 (2002).

Members of the family of the Green Fluorescent Protein (GFP) are the only known type of natural pigments that are essentially encoded by a single gene, since both the substrate for pigment biosynthesis and the necessary catalytic moieties are provided within a single polypeptide chain. In sharp contrast to the state of knowledge just three years ago when GFP was the only known protein of its kind, a whole family of related proteins, exhibiting striking diversity of features have now been identified. This provides new possibilities for a variety of studies ranging from applied biotechnology to evolutionary ecology.