TREX1 and familial chilblain lupus: Thus, N-terminal TREX1 mutations result in hyperactivation of the cGAS-STING pathway, causing inflammatory diseases such as Aicardi-Goutières syndrome (AGS) and Familial chilblain lupus (FCL) (Wang et al., 2022; Rice et al., 2007; Liu and Ying, 2023).