In order to regulate gene expression, cells utilize diverse molecular mechanisms, one of which is through mRNA modifications. In their study in Molecular Cell, the Shi Lab demonstrates that m6Am is an evolutionarily conserved mRNA modification that marks 5’ ends of mRNAs. In human cells, this mRNA modification is catalyzed only by PCIF1, a nuclear enzyme that binds CTD of RNA PolII. In this study, they further develop a genome-wide mapping methodology, m6Am-Exo-Seq, and generate a global map of this mRNA modification, which reveals a diverse set of methylated mRNAs in melanoma cells. Collaborating with Gygi and Adelman labs at HMS, they further show that m6Am does not alter mRNA transcription or stability, but it negatively impacts cap-dependent translation of methylated mRNAs in vivo and in vitro.