BCAT2 and maple syrup urine disease: No BCAT2 inhibitor has reached clinical trials yet, and one reason is the safety concern: systemic BCAT2 inhibition would raise circulating BCAA levels (as seen in genetic BCAT2 or BCKDH deficiencies), which can lead to metabolic complications such as insulin resistance or neurologic issues akin to maple syrup urine disease [107].