To define which immune cells mediate protective immunity during subcutaneous C. cassiicola phaeohyphomycosis, we infected monocyte/macrophage-specific CARD9-deficient Card9fl/flCx3cr1CreER mice (15) and found that CARD9 deficiency in monocytes/macrophages enhanced infection susceptibility relative to WT controls (Figure 3E). Here, CARD9 is linked to infection.