RAG2 and incontinentia pigmenti: For instance, the production of high levels of neutralizing IFN‐I auto‐Abs can be genetically driven and it has been described in several settings as young patients with APS‐1, carrying germline loss‐of‐function monoallelic or biallelic mutations in the autoimmune regulator (AIRE) gene, in subjects with hypomorphic mutations of RAG1 or RAG2 and combined immunodeficiency, in men with hemizygous mutations of FOXP3 and IPEX, and in women with heterozygous null mutations of X‐linked NEMO and incontinentia pigmenti.5