POFUT1 and breast cancer: Fucosylation is the process of adding fucose units onto a molecule through a process catalyzed by fucosyltransferases (FUTs) and protein O-fucosyltransferases (POFUTs)13, including POFUT1. Recent studies reveal that POFUT1 is closely associated with Dowling-Degos disease14, and certain solid cancers including breast cancer and liver cancer15–17.