Podoplanin also proved to be a valuable biomarker in the malignant transformation of all investigated OPMDs (oral leukoplakia: p < 0.001; erythroplakia: p = 0.05; oral lichen planus: p = 0.02; discoid lupus erythematosus: p = 0.009). Here, PDPN is linked to discoid lupus erythematosus.