Nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice were randomly categorized into U937R group, U937R-EV group, U937R-si-Nrf2 (silenced Nrf2) group, U937R-EV + Ara-C group, and U937R-si-Nrf2 + Ara-C group. This evidence concerns the gene NFE2L2 and severe combined immunodeficiency.