CARD9 and hyperinsulinemic hypoglycemia, familial, 4: CARD9 deficiency (MIM 212050) is characterized by the spontaneous development of invasive fungal infections due to fungi belonging the phylum Ascomycota. They include CMC (see “predisposition to CMC” section), invasive Candida infections (in particular of the CNS but also of the eyes, the colon and the bones), extensive and/or deep dermatophytosis, subcutaneous and invasive phaeohyphomycosis, as well as extrapulmonary invasive aspergillosis (248–250).