BCAT1 and lung adenocarcinoma: We found that inhibition of BCAT1 in lung adenocarcinoma cells increased the cellular contents of the three BCAAs and α-KG (Fig. 5A), which is illustrated by the schematic in Fig. 5B. In mammalian cells, there are more than 60 dioxygenases that utilize α-KG as a cosubstrate 20, 21.