CARD9 and viral infectious disease: However, in contrast to the predominant protective effect observed in fungal diseases, CARD9 signaling seems to play an ambivalent role in viral disorders, with beneficial effects by promoting antiviral responses (e.g., VSV, vaccinia virus) and detrimental effects by triggering virus-induced immunopathology (e.g., influenza virus, coxsackievirus) being described in animal experiments [36,37,38,39].