TF and neoplasm: PNA is a carbohydrate-binding protein (or lectin) and binds galactose-terminated glycans, in particular the oncofetal Thomsen-Friedenreich disaccharide (Galβ1-3GalNAcα-, the Thomsen-Friedenreich T or TF antigen) which is commonly overexpressed in >90% tumour cells (4) and is a natural ligand of the endogenous human galactoside-binding protein galectin-3 (5).