The document summarizes the structure and composition of fungal cell walls. Fungal cell walls generally have three layers: an outer layer of glycoproteins, a middle β-glucan layer, and an inner α-glucan layer. The α-glucan layer is composed mainly of α(1-3) glucan polymers but may also contain some α(1-4) glycosides. It plays a structural role stiffening the cell wall. The bulk of the cell wall consists of β(1-3) glucan polymers that form strong triple helix structures. Some fungi also contain chitin in their cell walls.