Infection with viable P. gingivalis caused 3.8 ( ± 1.7) fold up-regulation of PD-L1 expression at multiplicity of infection (MOI) of 10, increased to 9.3 ( ± 3.9) fold using MOI 100 and 11.3 ( ± 5.5) fold using MOI 500 (Figure 1). The gene discussed is CD274; the disease is infection.