Iwata et al. [3] reported a case in which IgA deposition in an IgAN patient disappeared after peripheral blood stem cell transplantation for acute lymphocytic leukaemia, suggesting that some circulating factors may play an important role in IgAN and that IgAN appears to be a systemic disease in which the kidneys are damaged as innocent bystanders. This evidence concerns the gene CD79A and acute lymphoblastic leukemia.