CRP and infection: For this purpose, we applied 10 μg/mL CRP in our oral mucosa and salivary gland model, as CRP concentrations of >8.7 μg/mL are associated with infections (together with high temperature), and clinically relevant concentrations of 10–20 μg/mL have also been used for studies with in vitro models of the blood–brain barrier previously [45,46].