Plaque assays reveal that the number of viable rickettsiae in circulating blood was higher in EPAC1-KO mice (n = 11) than wild-type (WT) mice (n = 10) at 30 min and 1 hr post-infection (p.i.)when the bacteria were given by the intravenous route (Figure 1A). This evidence concerns the gene RAPGEF3 and infection.