CASP9 and oral lichen planus: In addition, the immunohistochemistry staining assay showed increased Bcl2 and caspase 3 expression levels in OLP tissues and there was statistical significance (Figure 5,D), which further confirmed the corresponding results using miR‐27b‐3p in vitro, except that there was no statistical significance in caspase 9 expression level (Figure S1D), which may be due to the interference of various apoptotic regulatory pathways.