In analogy to the human disorders, mice either lacking Stim1 or Orai1, or carrying GoF mutations in these genes respectively recapitulate the main clinical signs of immunodeficiency or TAM/STRMK [19,20,21,22], and represent valuable tools to investigate disease progression, uncover the underlying pathomechanisms, and identify therapeutic targets. The gene discussed is ORAI1; the disease is immune system disorder.