Clinical evidence supports this mechanism: in sarcopenia patients, the activity of the rate-limiting enzyme for BCAA degradation, the branched-chain α-keto acid dehydrogenase complex (BCKDH), along with the expression of its upstream activator protein phosphatase Mg2+/Mn2+-dependent 1K (PPM1K), is significantly downregulated, directly contributing to intracellular BCAA accumulation. This evidence concerns the gene PPM1K and sarcopenia.