MAPK3 and lip and oral cavity carcinoma: Consequently, the expression of B7-H1 by oral carcinomas may aid their ability to evade immunity.366 Infection with P. gingivalis induces ERK1/2- Ets1, p38/HSP27, and PAR2/NF-KB signaling to promote expression of promatrix metalloproteinase (proMMP-9).360 In this process, P. gingivalis produces gingipains, which are cysteine proteinases with a dual function, and then binds to the PAR2 receptor, resulting in the maturation of the proenzyme MMP-9 into its active form.