SELE and periodontitis: Expression of these molecules enables the transportation of neutrophiles from the highly vascularized periodontium to the gingiva sulcus to reach the site exposed to bacterial challenge.[64] The significant upregulation of E‐selectin and ICAM‐1 that was observed in our model upon addition of LPS endotoxins, together with IL‐6 and IL‐8 upregulation, confirms that the “PDL‐on‐chip” can recapitulate the innate immune response found in vivo during periodontitis.