TNF and oral lichen planus: Zhang et al.27evaluated the nuclear factor‐κB‐dependent pro‐inflammatory cytokines, including TNF‐α, interleukin‐6 (IL‐6), and IL‐8 in serum and the saliva samples of OLP patients and healthy individuals; they suggested that saliva‐based test can be used as a cost‐effective adjunctive tool for measuring pro‐inflammatory cytokines in OLP patients.