Other monogenic conditions include dysfunction of NADPH oxidase complex, X-linked inhibitor of apoptosis (XIAP), lipopolysaccharide responsive beige-like anchor protein (LRBA), cytotoxic T lymphocyte-associated protein 4 (CTLA-4), STAT3, and chronic granulomatous disease (34). Here, CTLA4 is linked to chronic granulomatous disease.