PRKDC and severe combined immunodeficiency: In the review of studies that used mice as a model, the most used species was BALB/C nude [41,45,53,56,57,58,59,62] followed of Nude athymic [32,51,55,63,67] in eight (38%) and five (24%) studies, respectively; C57BL/6 in two studies (10%) [44,50] and the other six studies used different species of mice such as Mut6/cKO [64], Nonobese diabetic/severe combined immunodeficiency (NOD-SCID) [66], Swiss nude [34], CB17-SCID [52], ICR-Prkdc-SCID [48], and Rag2M [43], representing 5% each.