ADA and severe combined immunodeficiency: In our cohort NK numbers in patients with ADA-SCID were reduced at presentation (mean, 87 × 106/L), and thus data for patients with ADA-SCID were pooled with the NK−SCID group for overall analyses (n = 53), although reconstitution data were also considered independently given that a number of these patients received enzyme replacement therapy ahead of transplantation, which might have supported detoxification and partial lymphocyte recovery.