SAMHD1 and Aicardi-Goutieres syndrome: A link between AGS and lupus was highlighted by the discovery of TREX1, SAMHD1, RNASEH2A/B/C, and IFIH1 mutations in SLE patients (Lee-Kirsch et al. 2007; Cunninghame Graham et al. 2011; Ravenscroft et al. 2011; Günther et al. 2015).