A study demonstrated that in a mouse lung adenocarcinoma model, the intratumoral fungus Aspergillus sydowii activates MDSCs through the Dectin-1/CARD9/IL-1β pathway via β-glucan, mediating the activation of MDSCs and increasing the proportion of Tregs and PD-1+CD8+ T cells in the tumor microenvironment, thereby promoting tumor progression [29]. The gene discussed is CARD9; the disease is neoplasm.