Cathepsin G plays an important role in eliminating intracellular pathogens and breaking down tissues at inflammatory sites, as well as in anti-inflammatory response.

[11] The activity of cathepsin G depends on a catalytic triad composed of aspartate, histidine and serine residues which are widely separated in the primary sequence but close to each other at the active site of the enzyme in the tertiary structure.

[12] Cathepsin G has a specificity similar to that of chymotrypsin C, but it is most closely related to other immune serine proteases, such as neutrophil elastase and the granzymes.

[14] It localizes to Neutrophil extracellular traps (NETs), via its high affinity for DNA, an unusual property for serine proteases.

[15] Cathepsin G was also found to exert broad-spectrum antibacterial action against Gram-negative and –positive bacteria independent of the function mentioned above.