Cancer cells wear unusual sugar molecules on their surfaces — a phenomenon called aberrant glycosylation — that actively shut down the immune system's ability to detect and destroy them. These tumor-associated glycans engage inhibitory receptors on immune cells and interfere with the effectiveness of existing immunotherapies like checkpoint inhibitors. This review from researchers at Amsterdam UMC and the University of Porto surveys what is known about tumor glycosylation, how it reshapes the immune environment around a cancer, and what new therapeutic strategies are emerging to exploit or neutralize these sugar coatings. The findings suggest glycans could serve as both direct cancer drug targets and as tools to boost immunotherapy response, opening a new front in precision oncology.
