Mutations in four genes, NFKB1, STAT3, CTLA4, and PIK3CD, led to not only profound B cell defects but also significant immune dysregulation, including autoimmunity, lymphoid hyperplasia, and organ infiltrative granulomatous disease, complications described in other subjects with familial inheritance (3, 16, 24, 25). This evidence concerns the gene CTLA4 and Autoimmunity.