This protocol is a natural history study designed to investigate the clinical, microbiologic, genetic and immunologic correlates of primary immune deficiencies and other conditions associated with mucocutaneous and invasive fungal infections (IFIs). The hypothesis is that chronic mucocutaneous mycoses and IFIs are caused by abnormalities in immune function in these patients that can be identified using modern methods in molecular and cell biology and immunology. For inclusion, patients must have a history of or an active mucocutaneous or invasive fungal infection, but may or may not have a defined primary or acquired immunodeficiency state. Patients will undergo evaluations that include history/physical examination and blood, saliva, and possible tissue sampling for genetic and immunological testing. Patient relatives may also be screened for clinical, microbiological, genetic and/or immunological correlates of host defense abnormalities. Healthy volunteers will be enrolled as a source of control blood, saliva, and possible tissue sampling, and for genetic testing.