The authors of "Basal Activation of the P2X7 ATP Receptor ElevatesMitochondrial Calcium and Potential, Increases Cellular ATPLevels, and Promotes Serum-independent Growth" (Mol. Biol. Cell[2005] 16, 3260-3272; published online before print as 10.1091/mbc.E04-11-1025)would like to make a correction to their paper. On pages 3264and 3265, panel C of Figure 3 and panel E of Figure 4, the cytosoliccalcium concentration in the y axis should read nM, not µM.Corrected panels have been included below.