FUCA1 and breast cancer: Thus, reduced expression of α-L-fucosidase 1 (FUCA1) and increased expression of α1,6-fucosyltransferase (FUT8) lead to an increase in α1,3-linked fucose in the Lewis X antigen (LeX) and core residues of α1,6-linked fucose in N-glycans in breast cancer [97,98].