GoF mutations in PIK3CD (29, 67, 80–82), that signals via AKT and mTOR to control the development and activation of T and B cells, result in a complex immunodeficiency syndrome referred to as activated PI3K δ syndrome, characterized by recurrent infections, lymphoproliferation, autoimmunity, and an increased risk of lymphoid malignancies (83). This evidence concerns the gene PIK3CD and Autoimmunity.