N-acetylcysteine (NAC) downregulates type I insulin-like growth factor receptor (IGF-IR) and epidermal growth factor receptor (EGFR) on colorectal carcinoma cell lines – possible mechanism underlying NAC-mediated chemoprevention and chemotherapy - Kelly, RG; Nally, K; O'Sullivan, GC; Shanahan, F; O'Connell, J (Endoscopy, 2005)