“…The most common carcinogens in tobacco are benzopyrenes, 4-(methylnitrosamine)-1-(3-pyridyl)-1-butanone, and N -nitrosonornicotine (NNN) [38,39]. The metabolites of these compounds present in tobacco induce mutations that affect DNA replication and the genes involved in the control of cell growth, favoring damage to the oral mucosa and malignant transformation [40,41]. In Asia, a form of smokeless tobacco called Guthka is consumed, which is a mixture of betel nut (Areca catechu), tobacco, and spices.…”