This is one of the cellulases, enzymes involved in the hydrolysis of cellulose and related polysaccharides; more specifically, an exocellulase, that acts at the end of the polysaccharide chain. Other names for this enzyme are exo-1,4-β-glucosidase, exocellulase, exo-β-1,4-glucosidase, exo-β-1,4-glucanase, β-1,4-D-glucanase, exo-1,4-β-glucanase, and 1,4-β-D-glucan glucohydrolase.