Genetic and immunologic testing will be performed on all subjects (patients, relatives, and healthy volunteers) to evaluate for possible immunogenetic factors that lead to susceptibility to cryptococcosis. Among the aims of this protocol are to better understand the pathophysiology and genetic factors that lead to defects in host defense and to use modern and evolving methods in molecular and cellular biology to elucidate the pathogenesis of this particular susceptibility. A better understanding of the underlying pathophysiology of immune defects and genetic susceptibility to fungal infections could allow for the rational development of novel therapies for such diseases and to benefit future patients.