Dysbiosis of gut fungi may affect the function of caspase recruitment domain-containing protein 9 (CARD9), a susceptibility gene for autoimmune glomerulonephritis including IgAN, thereby the activation of inflammatory immunity and interleukin-17A-producing T helper cell, contributing to the development of CKD 36. The gene discussed is CARD9; the disease is autoimmune glomerulonephritis.