Figure 1: Ca2+ uptake by liver and heart mitochondria; effect of UCP inhibitors. Figure 2: Ca2+ uptake in SkM mitochondria from wild-type (WT) and Ucp3−/− mice, plus liver and kidney mitochondria from WT and Ucp2−/− mice. References 1 Kirichok, Y., Krapivinsky, G. & Clapham D. E . Nature. 427, 360–364 (2004). CAS Article PubMed Google Scholar 2 Trenker, M., Malli, R., Fertschai, I., Levak-Frank, S. & Graier, W. F. Nature Cell Biol. 9, 445–452 (2007). CAS Article PubMed Google Scholar 3 Graier, W.