Severe Combined Immunodeficiency, X-Linked, also known as x-linked severe combined immunodeficiency, is related to combined immunodeficiency, x-linked and severe combined immunodeficiency, autosomal recessive, t cell-negative, b cell-negative, nk cell-negative, due to adenosine deaminase deficiency. An important gene associated with Severe Combined Immunodeficiency, X-Linked is IL2RG (Interleukin 2 Receptor Subunit Gamma), and among its related pathways/superpathways are Innate Immune System and ERK Signaling. The drugs Busulfan and Mecasermin have been mentioned in the context of this disorder. Affiliated tissues include nk cells and t cells, and related phenotypes are lymphopenia and pneumonia