STK11 and esophageal squamous cell carcinoma: We found the RBM4 depletion-restricted glutamine utilization was mostly overcome by LKB1 reduction, which was previously reported to accelerate glutamine uptake and glutaminolysis.25 Pharmacological inhibition of AMPK, a critical LKB1 downstream kinase, has the similar restorative effect to LKB1 reduction, suggesting LKB1-AMPK axis may serve as a mediator in glutamine dependency of RBM4 high ESCC.