Glyceroneogenesis has a new PEP in its step(s).

Mitochondria generate phosphoenolpyruvate (PEP), although its export mechanism and physiological roles were unknown. In this issue of Cell, Kajimura and colleagues identify SLC25A35 as the mitochondrial PEP exporter and uncover a previously unrecognized role for mitochondrial PEP synthesis in glyceroneogenesis in adipose tissue and upon development of fatty liver disease.