PROS1 and periodontitis: In previous cellular and animal studies, certain TAM components, and in particular, Pros1 were down‐regulated by LPS stimulation or repeated P gingivalis infection.19, 34 In this study, both Pros1 and Tyro3 were down‐regulated by p.g‐LPS stimulation, as observed in hGECs as well as in periodontitis rats.