You are what you eat and translate: Feeding the code to fight cancer and viruses.

Extracellular arginine directly remodels the tRNA-codon axis, regulating MHC class I translation independently of amino acid stress signaling.

• Why it matters: Understanding how nutrients influence gene expression is crucial for developing new therapeutic strategies against cancer and viral infections, yet this mechanism remains largely unexplored.
• What they did: Wu et al. examined the effect of extracellular arginine on the tRNA-codon axis and its role in controlling codon-dependent translation of MHC class I mRNA, revealing a nutrient-sensing pathway.
• The result: This mechanism modulates immunity in colorectal cancer and viral infection, offering new opportunities for targeted therapeutic interventions.