These mice develop spontaneous autoimmune disease from about 3–4 months of age, in contrast to conditional knockout of Dicer in Foxp3+ cells (Foxp3CreDicerfl/fl), which results in spontaneous autoimmune disease that is fatal by 4 weeks of age (Liston et al., 2008a; Zhou et al., 2008b). This evidence concerns the gene DICER1 and autoimmune disease.