Although we have not yet specifically related TG2 activity to tissue compliance, our present in vivo observations with rodent models of metabolic syndrome (ZSF1 obese rats) and aging (SAMP8 mice) are consistent with participation of TG2 in cardiac and lung matrix changes that are associated with tissue stiffness in multiple cardiovascular and pulmonary diseases mediated by these conditions. Here, TGM2 is linked to lung disorder.