A similar application of the γ-retroviral vectors (murine) is present in ADA-SCID, a fatal PID with impaired T-, B-, and NK-cell growth, characterized by mutations in the gene coding for ADA (responsible for detoxifying the body of toxic purine metabolites), thus exposing patients to severe infections [9,16,17,18,26]. This evidence concerns the gene ADA and pelvic inflammatory disease.