CD4 and systemic lupus erythematosus: The studies reviewed in the articleentitled “Epigenetically Altered T Cells Contribute to Lupus Flares” inthis issue of Cells summarize these studies, and how they led to studies demonstratingsimilar changes in a subset of CD4+ T cells from patients with active lupus.Together the experiments indicate a mechanism by which environmental agents that causeinflammation can trigger lupus flares.