TREX1 and systemic lupus erythematosus: Similarly, Trex1-deficient mice or C57BL/6, FVB and NOD (CFN) mice (a triple cross between C57BL/6, FVB and NOD strains), both models for SLE and other autoimmune diseases, developed myocarditis along with the presence of MyHC-specific autoantibodies23,24.