To examine the physiological importance of the adhesion properties of ACE2 and ACE, adhesion assays were performed using primary human cardiac myofibroblast (CF) cells, important mediators of cardiac remodelling. All cells adhered strongly to fibronectin (data not shown), an important component of the extracellular matrix, adhesion to which is integrin-mediated [31] . A significant difference in cell binding was seen in the presence and absence of ACE2 ( Figure 5A ) in patient samples. The average fold increase in cell adhesion in the presence of ACE2 was 3.9 fold and p = 0.0035. Differences in adhesion to both fibronectin and ACE2 were seen in all patient cells ( Figure 5A ); this is likely due to an inherent variation in integrin and/or ACE2 expression levels since these were primary cells [32] . As previous experiments had shown ACE2 and ACE both bind integrins, investigations were performed to determine if ACE could also act as a cell substrate. Cells adhered comparably to both ACE and ACE2 ( Figure 5B ) and the presence of an RGD peptide had no effect on the adhesion to ACE or ACE2 (data not shown).