ACTA1 and oral lichen planus: [31] In previous studies, immunohistochemical observations demonstrated no expression of α-SMA in the epithelium and subepithelial tissue of and OLP mucosa, whether there are MFs located in OLP lesion is controversial.We immunostained the protein maker α-SMA and find that OLP buccal mucosa contains stromal cells expressing α-SMA.To identify these stromal cells, Immunohistochemical staining was used combined with observation of the morphology of the isolated cells.