Studies on the role of FPR2 have focused on the submandibular gland. The submandibular gland is one of the major salivary glands located under the floor of the mouth. Saliva is a watery fluid produced from salivary glands that contains various innate antimicrobial molecules, such as immunoglobulins, lysozyme, and lactoferrin. Decreased saliva production or the absence of saliva increases susceptibility to oral infection80. FPR2 and its ligand RvD1 reduce immune responses in the salivary glands. Fpr2 knockout mice were found to show an enhanced immune response in the salivary gland in an LPS challenge model. These knockout mice exhibited abnormalities such as increased immune cell infiltration in the salivary gland, upregulation of inflammatory cytokines, decreased saliva production, increased apoptosis, and alterations in tight junction proteins89. RvD1 activates FPR2 on the salivary glands and helps to maintain salivary gland integrity and to inhibit apoptosis and TNF-α-mediated inflammation90,91.