We have previously characterized a humanized mouse model of IgA nephropathy, the α1KI-CD89Tg mouse (21), that overexpresses both human CD89 IgA receptor on myeloid cells and human IgA1 and develops circulating hIgA1-sCD89 complexes with mesangial IgA1 deposits associated with clinical features of renal injury including hematuria and proteinuria. This evidence concerns the gene IGHA1 and IgA glomerulonephritis.