RAD52 and systemic lupus erythematosus: Zinc-finger protein 318 (ZFP318) is essential for IgD expression mainly via modulating alternative mRNA splicing.223 The key homologous recombination factor, radiation-sensitive 52 (Rad52) mediates IgD class-switch DNA recombination in concert with ZFP318 downregulation, and Rad52 phosphorylation is associated with high levels of IgD autoantibodies in SLE patients and in lupus mice.224