ADA and severe combined immunodeficiency: A variety of genes are involved in this disease, such as common gamma chain (γc) of interleukin 2 receptor (IL2RG) in X-SCID, adenosine deaminase (ADA) in adenosine-deaminase-deficient SCIDs (ADA-SCID), and DNA cross-link repair protein 1C (DCLRE1C) in Artemis-deficient SCIDs (ART-SCID) that are the most common types of SCID in GT approaches [2,30,31].