The super-killer (SKI) complex component SKIV2L, encoding a subunit of the RNA exosome responsible for RNA degradation, is a potential susceptibility gene for human SLE.71 Mutations in the human SKIV2L gene cause tricohepatoenteric syndrome characterized by immunodeficiency, severe diarrhea, skin and hair abnormalities. Here, SKIC2 is linked to immunodeficiency disease.