Differentially expressed miRNAs are detected in serum and salivary exosomes compared to healthy samples, which may be promising biomarkers for periodontitis.15,208,209 Patients with periodontitis could be differentiated from both healthy controls and gingivitis patients by the global 5mC hypermethylation in salivary sEVs.210 Yu et al.211 identified higher levels of PD-L1 mRNA in salivary exosomes of periodontitis patients, correlating with the stages of periodontitis. The gene discussed is CD274; the disease is periodontitis.