A hot water extract from cordyceps (Cordyceps militaris) has shown powerful immune-boosting effects by activating key immune cells called dendritic cells. This is thanks to a natural compound in the mushroom, 1,3-β-glucan, which works through a receptor called dectin-1. The extract increased immune signals like TNF-α by over 50 times (from 7.8 to 403.7 pg/mL), helping the body fight infections and stay healthy.