TLR7 and systemic lupus erythematosus: To determine the role of PPP2R2D-deficient T cells in regulation of lupus-related pathology, we applied imiquimod, a TLR7 stimulator, to the ear skin of 8-week-old R2Dfl/fl and LckCreR2Dfl/fl mice to induce lupus-like disease, as previously described (24).