Cryptococcus neoformans and Cryptococcus gattii are the two etiologic agents of crypto coccosis. They belong to the phylum Basidiomycota and can be readily distinguished from other pathogenic yeasts such as Candida by the presence of a polysaccharide capsule,. formation of melanin, and urease activity, which all function as virulence determinants.| Infection proceeds via inhalation and subsequent dissemination to the central nervous system to cause meningoencephalitis. The most common risk for cryptococcosis caused c" by C. neoformans is AIDS, whereas infections caused by C. gattii are more often reported in immunocompetent patients with undefined risk than in the immunocompromised. There havebeen many chapters, reviews, and books written on C. neoformans. Thetopics wefocus on in this article include species description, pathogenesis, life cycle, capsule, and stress response, which serve to highlight the specializations in virulence that have occurred in this U | uniqueencapsulated melanin-formingyeast that causes global deathsestimated at more tan 600,000 annually.