 Systemic lupus erythematosus is an autoimmune disease in which antibodies directed against self antigens, including nucleic acids complexed with proteins, cause tissue damage. This process involves the activation of autoreactive B cells by CD4 plus T cells through cytokines and cell-to-cell contact, leading to inflammatory phenotypes in lupus. B cells also have other effector functions such as antigen presentation and cytokine secretion, which contribute to the disease process. This article was authored by Sanctual Choi and Lawrence Morel.