CXCL8 and oral lichen planus: Researchers also have identified the up‐regulation of IL‐17A in OLP lesions and saliva,34, 35, 36 and we have previously found that exogenous IL‐17 could significantly enhance the mRNA expressions of CCL‐20, IL‐8 and tumour necrosis factor‐α in normal oral keratinocytes.37