In a paper published online in advance in Cell this week, investigators at the University of Vienna and the Hebrew University-Hadassah Medical School show that the toxin MazF "cleaves at ACA sites at or closely upstream of the AUG start codon of some specific mRNAs and thereby generates leaderless mRNAs." The team also reports on a subpopulation of ribosomes that it says "selectively translates the described leaderless mRNAs both in vivo and in vitro."