Surprisingly, only three mRNAs were downregulated in both groups—the 3′-exonucleases TREX1 and TREX2 and the fanconi anaemia complementation group F gene, FANCF. Mutations in TREX1 have been associated with several human diseases including systemic lupus erythematosus and retinal vasculopathy with cerebral leukodystrophy (RVCL)16, 17, 18. Here, TREX2 is linked to systemic lupus erythematosus.