EYFP is a yellow fluorescent protein with an excitation peak of 513nm and an emission peak of 527nm in vitro. It is an artificial derivative of the naturally occurring fluorescent protein encoded by the Aequorea victoria GFP gene (UniProtKB:P42212), containing the mutations S65G, V68L, S72A and T203Y relative to the wild-type GFP sequence (PMID:8703075, PMID:20664080).