Whereas major inroads have been made into genomics, metabolomics, or protein and lipid research, glycosylation remains largely unexplored at the proteome scale. There are limited technologies for profiling the complex glycoproteome. Glycoproteins can differ not only by the number and location of glycosites, but also by the composition and structure of each glycan. Glycoproteomics is “one of the key frontiers of life sciences,” says study leader Josef Penninger, MD, IMBA Director.