PRTN3 and infection: During the response to infection by pathogens, plants activate specific PR protein groups with different molecular functions, such as PR-2 (a β-1,3-glucanase), PR-3 (a chitinase family), PR-5 (a thaumatin-like), PR-10 (a ribonuclease-like), PR-12 (a defensin), PR-13 (a thionin), and PR-14 (a lipid-transfer protein) for example [57].