PTGS1 and infection: Regarding the relative expression of COX-1, it was upregulated after infection of PHGFs by the ATCC T2 P. gingivalis strain, and it was significantly elevated in comparison with COX-1 expression after infection with control wt-P. gingivalis (ATCC 33277 strain, p < 0.001) and infection with the P. gingivalis strain without the polymorphic variant obtained from a donor with advanced PD (G231N, E232T, N235D- adv, p < 0.0001).