NLRC5 gene expression was silenced using two independent siRNAs [Thermo Fisher Scientific; siNL#1 (siRNA HSS130675): 5′-GGACACCUGGCAGUCUUUCAUUCAU-3′; siNL#2 (siRNA HSS130676): 5′-GCAGUUGGCAGAGUCUCUCGUUCUU-3′]. AllStars Negative Control siRNA (siCTL) (Qiagen) was used as a negative control; the siRNA control does not interfere with β cell gene expression, function, or viability (82 (link)). NOVA1 gene expression was silenced using an siRNA [Thermo Fisher Scientific; siNO1 (siRNA HSS143142): 5′-UUUGCAACUGAACAAUUGUCUGUCC-3′] (44 (link)). Cells were transfected using the Lipofectamine RNAiMAX lipid reagent (Invitrogen, Life Technologies) in Opti-MEM (Gibco, Thermo Fisher Scientific) reduced serum medium, according to the manufacturer’s instructions. EndoC-βH1 was transfected using 30 nM of each siRNA, overnight. Dispersed human islets and SC-derived β-like cells were transfected with 60 nM of each siRNA, also during an overnight incubation period. After transfection, EndoC-βH1, dispersed human islets, and SC-derived β-like cells were kept in culture for a 48-hour recovery period and subsequently exposed, or not, to human IFNα (2000 U/ml; PeproTech) for 8 or 24 hours. These conditions are based not only on previously published time dose-response experiments (8 (link)) but also on time course and dose response experiments presented in this article (fig. S4).