MTHFD1 and neuroblastoma: Methylenetetrahydrofolate dehydrogenase 1 (MTHFD1) is positively correlated with MYCN expression, and ChIP‒qPCR and dual-luciferase reporter assays have revealed that MYCN directly activates MTHFD1. Knockdown of MTHFD1 reduces the NADPH/NADP (+) and GSH/GSSG ratios, increases reactive oxygen spieces (ROS), and inhibits NB cell proliferation and migration.