IL2 and systemic lupus erythematosus: In human SLE, a relative deficiency of IL-2 production in activated T-cells, by a mechanism of transcriptional repression, is well documented [17], and a functional relevance of impaired IL-2 production was directly demonstrated for lupus manifestation in NZB/W F1 mice [18], as it had been for other mouse autoimmunity models [19].