Updated project metadata. The total liver proteomes of postnatal-day-7 mice with liver-specific UBA3 deficiency and their littermate controls were compared by two-dimensional (2-D) electrophoresis mapping. 25 protein spots were obviously changed in their expression upon UBA3 deficiency. These 25 protein spots were excised from 2-D gels. After in-gel digestion, the tryptic digests were subjected to mass spectrometric analysis by LC–MS/MS, followed by database searching. Here, we identified ETFA expression in spot 14, which was decreased in UBA3-deficient conditions.