Axons can extend to lengths that are more than 1000-fold longer than the neuron’s cell body diameter. As such, localized synthesis of new proteins in distal axons provides a level of autonomy to respond to extracellular stimuli. Both growth-promoting and growt-inhibiting stimuli regulate intra-axonal protein synthesis to support directional growth and branching of axons. In their new study titled "Selective axonal translation of prenylated Cdc42 mRNA isoform supports axon growth", Seung Joon Lee, Matt Zdradzinski and their colleagues discovered that two Cdc42 mRNAs that encode two different variants of the Rho GTPase Cdc42 have distinct distributions and functions in neurons. They notably report that the alternative splicing of the Cdc42 gene product generates a locally synthesized prenyl-Cdc42 protein that promotes axon growth. Great work!