TREX1 and systemic lupus erythematosus: Trex1 deficiency or mutation, on the other hand, is associated with systemic lupus erythematosus (SLE), chilblain lupus and the human disease Aicardi-Goutières syndrome (AGS) (Lee-Kirsch et al., 2007a, 2007b; Stetson et al., 2008) and in this case inflammation is initiated from non-haematopoietic cells via a STING-dependent pathway (Gall et al., 2012).