Results for type II IP3R at 10 M IP3, 5 M ATP, and 50 M Ca2+ for the rates q24 and q42 linking the two modes (Fig. 3). These histograms were obtained by a fit to one representative record from one cell for a given combination of ligands. Mean values, μ, and standard deviations, σ, of the probability distributions are shown above the histograms and indicated in the plot by asterisks and arrows.