Dr. Adnan Halim is a biochemist specializing in mass spectrometry-based glycoproteomics. He obtained his Ph.D. from Gothenburg University, Sweden, in 2012, where he developed methods based on hydrazide chemistry to enrich N- and O-linked glycopeptides from human tissues. This approach led him to discover O-GalNAc linkage to tyrosine residues on amyloid-beta peptides from human cerebrospinal fluid. In 2012, Adnan was recruited to Copenhagen Center for Glycomics (CCG), where he pursued his postdoctoral training and interest in mass spectrometry, protein glycosylations, and precise genome editing. At CCG, Adnan focused on the elusive O-linked mannose modification in eukaryotes. He made major breakthroughs in this field by discovering cadherin/plexin O-mannosylations and the TMTC1-4 glycosyltransferases (GT105). Adnan was promoted to associate professor/group leader at CCG in 2016. Using a combination of techniques, including CRISPR/Cas9 engineering in cell lines and advanced mass spectrometry, his team is currently exploring the functions and regulations of non-classical O-Man glycosylations in mammalian systems.