IL13 induces the same biological effects as IL4 in normal human B cells. We show that as in the IL4R complex, both IL4Rα and IL2Rγc are components of the IL13R and that both cytokines induced STAT6, STAT3 and STAT5 activation in B cells. In spite of this similar downstream signalling, IL4 and IL13 used a different set of Janus kinases: IL13 is unable to activate JAK1 and JAK3.
