IL10 and infection: The kinetics of the IL-10–GFP response were, however, heterogeneous in the different tissue sites over the course of infection; the numbers of IL-10-producing cells declined rapidly from a peak on day 7 of infection in the spleen, whereas the expansion and contraction were more gradual in the other organs, with the exception of the Peyer's patches, where there was no significant increase in the numbers of IL-10–GFP+ events throughout the course of infection (Fig. 1C).