Fig. 4

Site-specific N-glycan types of recombinant SARS-CoV-2 S proteins expressed in human cells (a), insect cells (b), or from native S protein (c). The Y-axis of the histogram refers to the number of published papers that report the corresponding sites with detailed site-specific N-glycan types. The proportion in the pies represents the glycan types reported in the relevant papers. The region of RBD and the furin cleavage site are marked