TGM2 and neoplasm: Recent experimental studies by Dae-Seok Kim et al. demonstrated that inhibition of TGase 2 using siRNA, cystamine, glucosamine or R2 peptides promotes cell death in drug-resistant cancer cells via NF-κB inactivation [29]; However, Barnes et al. [30] suggested that reduced TGM2 activity is associated with tumor growth and metastasis, while Fesus et al. reported that increased activity of TGM2 in cells undergoing apoptosis indicates a pro-apoptotic function [31].