CD79A and IgA glomerulonephritis: IgA nephropathy is a disorder of B-cell regulation, with kidney pathology characterized by mesangial IgA-containing immune complex accumulation.1,10,11 It is noteworthy that both the pathogenic forms of IgA (commonly measured as galactose-deficient IgA1 [Gd-IgA1]) and the antibodies that recognize Gd-IgA1 are produced by B-lymphocyte−derived plasma cells.1,10,11 Therefore, a targeted approach to modulate B-cell activity is mechanistically congruent.