The data for DP2 receptor-mediated stimulation of eosinophils are the geometric means of the EC50 values with the 95% confidence limits shown below in brackets. The data for DP1 receptor-mediated elevation of cAMP levels in platelets are geometric means of the EC10 values with 95% confidence limits. EC10 values are the concentrations of prostanoids required to elevate cAMP to a level equivalent to 10% of the maximal response to PGD2, always determined in the same experiment. All values were calculated from the individual experiments used to calculate the data shown in Figs. 1-4. The numbers of experiments for each determination are given in the relevant figure legends.