Altogether, these data indicate that the result of in vivo development of IL-10 producing B cells is in principle detectable without restimulation (S1E and S1G Fig), but the data from egg-injected IL-10 reporter mice also suggest that an ex vivo SEA restimulation is required to visualize its full IL-10 potential, something which will happen in vivo during a natural infection due to the constant production of eggs and the high levels of circulating antigens. Here, IL10 is linked to infection.