Probability distribution as a measure of cell-to-cell stochastic variability.

Probability distribution of activated molecules under strong (top) , intermediate (middle), and weak (bottom) stimuli. Histograms were obtained using single cell activation data from a population of 100 cells. For the strong stimulus (top) probability distributions are shown for three time points T = 100, T = 500, and T = 1000. For the intermediate stimulus (middle), probability distributions are shown for three time points T = 500, T = 2000, and T = 4000. For the weak stimulus (bottom), probability distributions are shown for three time points T = 500, T = 2000, and T = 4000.