MAP2K4 and liver failure: In a recent manuscript in Cell, a first-in-class small molecule inhibitor of the kinase MKK4 (mitogen-activated protein kinase kinase 4) was described that greatly enhances liver regeneration after partial hepatectomy in animal models, with an excellent safety profile in humans.1 The findings of Zwirner et al. hold promise to alter the clinical management of liver failure in critically ill patients.1