STK11 and lung cancer: The application of CB-839 could markedly halt the enhanced RBM4-induced acceleration of glutamine consumption and glutamate secretion in ESCC cells (Supplementary Fig. 6e), therefore, we sought to investigate whether RBM4-induced glutamine preference could endow ESCC cells with intrinsic vulnerability, sensitizing ESCC cells to the glutaminase inhibitor CB-839, which is similar to the consequence of LKB1 deficiency in lung cancer.