Two distinct translation programmes exist for proliferation and differentiation, indicates a new study by Gringold et al. Using microarrays to measure the expression levels of tRNAs from differentiating or proliferating cells, the researchers show that the expression of pools of tRNAs expressed in either cellular state is mutually exclusive: tRNAs that are induced in proliferating cells are repressed in differentiating cells and vice versa. In addition, the tRNAs associated with each particular cell type carried anticodons that are part of a codon usage signature particular to proliferation or differentiation. These distinct translational programmes may have arisen to ensure stable cell fate decisions.