This differential effect on the expression of CD5 and IL-10 in PerC B cells resulting from SEA stimulation in vitro and infection in vivo might be due to the fact that PerC B-1a cells identified by surface marker CD5 were competent to secrete a large amount of IL-10 [35], and that PerC B-1a cells migrated into the liver to improve hepatic fibrosis induced by schistosome infection [46]. The gene discussed is CD5; the disease is infection.