Our previous metabolomic analysis of KspCre;Pkd1ΔC/flox cystic kidneys in newborn mice highlighted an impairment in the aminoacyl-tRNA pathway as well as an imbalance in amino acid biosynthesis (Podrini et al, 2018), suggesting that the amino acid response (AAR) could be the driver for ASNS upregulation in PKD. The gene discussed is ASNS; the disease is Renal cyst.