Interleukin 7 (IL‐7) expression was high in the presence of TSC, and it is known that IL‐7 is necessary for thymocyte survival and has an important role in the differentiation of T cells; indeed, mutations in IL‐7 gene and its receptor have been implicated in severe combined immunodeficiency.53, 54. This evidence concerns the gene IL7 and severe combined immunodeficiency.