Exogenous glucocerebrosidase is administered intravenously into patients and glucocerebrosidase preparation currently involves either extraction directly from human placenta or recombinant expression in CHO cells (Cerezyme ® ), which requires in vitro post-purification exoglycosidase digestions to unravel the trimannose core (Man 3 GlcNAc 2 ) using a combination of sialidase, galactosidase, and N-acetylglucosaminidase.