RAG1 and severe combined immunodeficiency: In these studies, BCG vaccination of severe combined immunodeficiency (SCID) or recombination-activating gene 1 (rag1)-deficient mice induced protection against subsequent lethal Candida albicans (C. albicans) infection via a mechanism that requires macrophages and proinflammatory cytokine production, both prototypical innate immune components [9, 16, 19].