ADA2 and systemic lupus erythematosus: Monogenic forms of SLE often involve mutations in genes that modulate the metabolism of nucleic acids (e.g.,DNASE1, DNASE1L3, IFIH1, RNASEH2A/B/C, ADA2, and SAMHD1) or mediate nucleic acid sensing (e.g., TLR7, UNC93B1, IFIH1, ACP5, TMEM173), leading to excessive type I IFN signaling43.