ADA and severe combined immunodeficiency: A recent publication analyzed hematopoietic clonal diversity via insertion site retrieval in children with adenosine deaminase-deficient severe combined immunodeficiency treated with retroviral gene therapy, revealing massive expansion of a CD56dim NK cell clone coincident with EBV reactivation post- transplantation (48).Other reports also suggest important roles for NK cells in response to EBV in human (49, 50).