IGHG3 and systemic lupus erythematosus: It's well documented that activated/memory helper T cells (CD4+CD44+CD62L− effector T cells, Teff), especially IFN-γ-producing Th1 subset, are responsible for inciting human and murine lupus, in part through increased production of highly nephritogenic Th1-related Ig2a and IgG3 autoantibodies [5]–[8].