Given prior suggestion that ZAP70 inhibition might be therapeutically efficacious in autoimmunity (Rao et al. 2021; Visperas et al. 2017), and the genetic parallel to TYK2 where an allelic series involving distinct immunodeficiency and autoimmune protective alleles led to a recently approved therapeutic, we sought to further elucidate the function of this novel protective genetic association to autoimmune disease. Here, TYK2 is linked to Immunodeficiency.