Other kidney conditions may also have IgA deposits, especially systemic lupus erythematosus (SLE)-associated nephritis, but this can usually be distinguished by the typical so-called “full-house” positive immunofluorescence staining for IgG, IgA, IgM, C1q, and C3 in SLE [7]. The gene discussed is C3; the disease is systemic lupus erythematosus.