Familial chilblain lupus or TREX1-associated systemic lupus erythematosus is an autosomal dominant autoinflammatory disease caused by either loss-of-function mutations in TREX1 and SAMHD1 genes or gain-of-function mutations in the TMEM173 gene, both leading to type I IFN overproduction (152–154). Here, SAMHD1 is linked to systemic lupus erythematosus.