Immunohistochemical expression of polo-like kinase 1 in oral squamous cell carcinoma and oral submucous fibrosis.

Context: Polo-like kinase 1 (PLK1) is a critical molecule in the proliferation of several human cancers. Overexpression of PLK1 has been correlated with cancer cell proliferation and lower overall survival rates. Although PLK1 has been studied in various tumors, information regarding its expression in oral cancer and precancer is limited.