PTPMT1: connecting cardiolipin biosynthesis to mitochondrial function

Cardiolipin, a phospholipid component of the inner mitochondrial membrane, is required for mitochondrial metabolism. In this issue, Zhang et?al. (2011) highlight a critical role for PTPMT1, a mitochondrial phosphatase, in cardiolipin biogenesis and possibly in cardiolipin deficiency diseases. Their findings also unveil a yet uncharacterized pathway affecting cell growth.