mCer is a monomeric cyan fluorescent protein. It is an artificial derivative of the naturally occurring fluorescent protein encoded by the Aequorea victoria GFP gene (UniProtKB:P42212), derived by mutagenesis of Cerulean, containing the A206K mutation that disrupts dimerization in addition to those present in Cerulean (PMID:17481360). The absorbance and emission spectra of mCer are very similar to that of ECFP (PMID:16716067).