These decreased proteins include those whose dysfunction is associated with various dysregulated metabolites we identified in Pptc7 KO tissues: Aldh4a1 (hyperprolinemia)47, Pcca, Pccb, Acad8, and Ivd (BCAA and catabolite acylcarnitine accumulation)48, and Etfa and Etfdh (medium and long-chain acylcarnitine accumulation)35 (Fig. 5k, l). This evidence concerns the gene ALDH4A1 and hyperprolinemia.