Screening for N-glycans carrying oneor more fucose residues together with α(2,3)-sialylation wouldallow us to identify the presence of the sLex antigen [Neu5Ac-α(2,3)-Galβ(1,4)-[Fucα(1,3)]-[NAcGlcβ]-],also known as CD15, whose overexpression is a frequent event in severaltypes of cancers, including CRC. Here, FUCA1 is linked to cancer.