SOCS1 (Suppressor of cytokine signaling 1) is part of negative-feedback signaling pathways downstream of cytokine receptors, including the interferon gamma receptor, that downregulates STAT-mediated signals, and a protein truncating mutation in SOCS1 was causally related to primary immunodeficiency (Thaventhiran et al., 2020). This evidence concerns the gene SOCS1 and inborn error of immunity.