Fungal infections represent a serious health problem in industrialized countries. In particular, multimorbid patients are highly susceptible to life-threatening infections by opportunistic fungi, most often Candida or Aspergillus species. In Europe, fungal infections account for 17% of intensive care unit infections. In addition, common non-life-threatening superficial infections impose significant restrictions on patients, resulting in a reduced quality of life. One of the first steps of pathogens during infection of the host is to attach to the surface of host tissues. This step in host-pathogen interaction is crucial for colonization by the pathogen and for the persistance of the pathogen in the host. Commensal organisms, such as Candida albicans, are able to persistently colonize the host without causing symptoms. However, the balance between commensalism and pathogenicity is delicate. How these two states are modulated during C. albicans colonization is a major area of research in medical mycology, with the aim of utilizing the knowledge gained for the benefit of the patient.