STAT1 and oral lichen planus: Utilizing immunofluorescence/immunohistochemistry (IF/IHC), we analyzed the presence and distribution of CD4 + and CD8 + infiltrating lymphocytes, CD163/STAT1 + macrophages, and expression of PD-1/PDL-1 in the epithelial compartment of biopsy samples previously diagnosed with OLP and OED.