To gain insight into the binding site of the CRC cell receptor Gal-GalNAc and whether both receptors can bind to Fap2 simultaneously, we docked the Gal-GalNAc disaccharide attached to Thr, as used in our binding experiment (Fig. 3a) and as present in most O-glycosylations in the colon on mucin-260, to Fap2-ECD. This evidence concerns the gene MUC5AC and colorectal carcinoma.