IL2RA and severe combined immunodeficiency: For example, both JAK1 and JAK3 have been implicated in IL-7R-mediated SCID [36], and IL-2R and JAK1 in JAK3-mediated SCID [37], with downstream STAT5 playing a role in the SCID phenotypes mediated by either IL-2Rγ [35] or JAK3 [37].