MYC and neoplasm: In a study of hepatocarcinogenesis in rats, animals fed a choline-deficient diet for 3 or 6 months, followed by a choline-supplemented diet, had a higher incidence of tumours and more amplification of the c-myc oncogene than did animals fed a choline-deficient diet continuously, suggesting the role of choline in tumour development (Chandar and Lombardi, 1988; Chandar et al, 1989).