CARD9 and Immunodeficiency: Similarly, of the myriad of known neutrophil specific immunodeficiencies caused by genetic abnormalities linked to Candida infection, including Dectin-1, CD18, CARD9, MPO, and enzymes of the NADPH oxidase pathway (6), to date chitotriosidase has not been linked in an increase in fungal susceptibility (6, 27).