Serendipitously, key genes involving the catabolism of BCAA, which produce propionic acid (C3:0) (Fig. 7A) for odd-chain FA endogenous biosynthesis and transformation, were downregulated significantly such as ACADS, ACADSB, and BCKDHA co-occurred with markedly enhanced BCKDK expression in colon cancer through The Cancer Genome Atlas database (Fig. 7B). The gene discussed is BCKDHA; the disease is malignant colon neoplasm.