Previous research by the authors highlighted that arecoline, a known risk factor for OSCC, increases phosphodiesterase-4A (PDE4A) activity in TGFβ activated buccal mucosal fibroblasts, which contributes to the development of oral submucous fibrosis (OSF), a precancerous condition [197]. The gene discussed is PDE4A; the disease is oral submucous fibrosis.