Real-time PCR analysis of EPAC1 expression. (A) EPAC1 real-time PCR threshold cycle (C_T) as a function of cDNA input from representative B-CLL, resting, and CD40 ligand-activated B cells. (B) Comparable analysis for rRNA using the same cDNA dilutions from the same cell populations. (C) Relative EPAC1 transcript expression in B-CLL and either resting (left) or CD40-ligand-stimulated (right) B cells. The mean and SEM of data from 3 sets of each cell type are shown.