As a key adaptor molecule in the downstream signaling of several C-type lectin receptors, CARD9 deficiency may lead to different fungal infections, including mucocutaneous or invasive candidiasis, deep dermatophytosis, phaeohyphomycosis, extrapulmonary aspergillosis, mucormycosis and trichosporosis (10–15). Here, CARD9 is linked to fungal infectious disease.