For example, truncated O-glycans including GalNAcα- (Tn), Neu5Acα2,6-Tn (sTn) Galβ1,3-GalNAcα- (TF), Neu5Acα2,6-TF, and Neu5Acα2,3-TF are found in breast, prostate, colon, respiratory, pancreas, ovarian, and gastric cancers. Here, TF is linked to gastric cancer.