INTRODUCTION
The basal stem cell layer of normal oral mucosa (NOM) is a self-perpetuating reservoir of cells with a mechanism for self-renewal, a property referred to as clonogenicity or stemness. The integrity of the basal stem cell layer is thus essential for epithelial homoeostasis. Breakdown in cell-cycle turnover is antecedent to the development of oral potentially malignant disorders (OPMDs) and oral squamous cell carcinoma (OSCC). Oral submucous fibrosis (OSF) is an OPMD commonly present among people in the Indian subcontinent and Southeast Asia.1–2 Various epidemiological studies implicate areca nut chewing as the main aetiological factor in OSF. There is overwhelming evidence suggesting that the chewing of commercial addictive products, such as pan masala, gutka, mawa and betel quid (BQ) containing considerable amounts of areca nut, tobacco and slaked lime, predisposes patients to OSF.1,3 Areca nut has cytotoxic effects on oral mucosal cells,4 and disturbingly, oral cancer arising in the background of OSF seems to develop earlier and has a greater propensity to invade and metastasize.