Cardiolipin, the specific phospholipid of mitochondria, is involved in the 
biogenesis, the dynamics, and the supramolecular organization of mitochondrial 
membranes. Cardiolipin acquires a characteristic composition of fatty acids by 
post-synthetic remodeling, a process that is crucial for cardiolipin homeostasis 
and function. The remodeling of cardiolipin depends on the activity of tafazzin, 
a non-specific phospholipid-lysophospholipid transacylase. This review article 
discusses recent findings that suggest a novel function of tafazzin in 
mitochondrial membranes. By shuffling fatty acids between molecular species, 
tafazzin transforms the lipid composition and by doing so supports changes in 
the membrane conformation, specifically the generation of membrane curvature. 
Tafazzin activity is critical for the differentiation of cardiomyocytes, in 
which the characteristic cristae-rich morphology of cardiac mitochondria 
evolves. This article is part of a Special Issue entitled Phospholipids and 
Phospholipid Metabolism.