In humans, loss‐of‐function mutations of STIM1 lead to severe combined immunodeficiency, autoimmunity, myopathy, and ectodermal dysplasia, whereas gain‐of‐function mutations cause the York and Stormorken syndromes (Online Mendelian Inheritance in Man [OMIM], 2017a, 2017b; OMIM, 2020, 2022; Feske et al., 2006; Lacruz & Feske, 2015). Here, STIM1 is linked to immunodeficiency disease.