title: Letter.
references.citation: Carcinogenesis. 1994 Jun;15(6):1219-26
references.pmid: 8020159
references.citation: J Natl Cancer Inst. 1980 Jan;64(1):177-206
references.pmid: 6986002
references.citation: Virchows Arch A Pathol Pathol Anat. 1971;352(2):157-64
references.pmid: 5313209
references.citation: Carcinogenesis. 1988 Jun;9(6):1049-54
references.pmid: 2967125
references.citation: Lab Invest. 2000 Sep;80(9):1399-411
references.pmid: 11005208
references.citation: Carcinogenesis. 1998 Dec;19(12):2069-80
references.pmid: 9886559
references.citation: Gan. 1984 Oct;75(10):876-83
references.pmid: 6150874
references.citation: Int J Oncol. 1997 Feb;10(2):261-8
references.pmid: 21533371
references.citation: Carcinogenesis. 1987 Nov;8(11):1607-12
references.pmid: 3664953
references.citation: Asian Pac J Cancer Prev. 2001;2(1):27-42
references.pmid: 12718652
references.citation: Carcinogenesis. 1994 Nov;15(11):2467-73
references.pmid: 7955093
references.citation: J Toxicol Pathol. 2012 Sep;25(3):189-99
references.pmid: 22988337
references.citation: Cancer. 1983 Jun 15;51(12):2197-205
references.pmid: 6303546
references.citation: Virchows Arch B Cell Pathol. 1973 Aug 21;13(4):267-96
references.pmid: 4355870
references.citation: Toxicol Pathol. 2005;33(4):477-83
references.pmid: 16036865
references.citation: Pathol Res Pract. 1994 Jun;190(6):513-77
references.pmid: 7984516
references.citation: Adv Enzyme Regul. 1984;22:97-121
references.pmid: 6591771
references.citation: J Clin Pathol. 1973 Mar;26(3):217-23
references.pmid: 4700503
references.citation: Carcinogenesis. 1988 Mar;9(3):387-94
references.pmid: 3345580
references.citation: Toxicol Pathol. 1989;17(4 Pt 1):685-8; discussion 688-9
references.pmid: 2697943
references.citation: World J Gastroenterol. 2012 Dec 14;18(46):6701-8
references.pmid: 23239906
references.citation: Carcinogenesis. 1994 Jun;15(6):1235-42
references.pmid: 8020161
references.citation: J Bioenerg Biomembr. 1997 Aug;29(4):303-13
references.pmid: 9387091
references.citation: Carcinogenesis. 1982;3(12):1429-36
references.pmid: 7151256
references.citation: Carcinogenesis. 1994 Jun;15(6):1227-34
references.pmid: 8020160
references.citation: Int J Toxicol. 2011 Mar;30(2):162-73
references.pmid: 21300768
references.citation: Carcinogenesis. 1985 Nov;6(11):1641-8
references.pmid: 2865015
references.citation: Carcinogenesis. 1986 May;7(5):689-95
references.pmid: 2870822
references.citation: Carcinogenesis. 1983;4(5):595-603
references.pmid: 6850991
references.citation: Toxicol Pathol. 1995 Sep-Oct;23(5):591-605
references.pmid: 8578102
references.citation: Virchows Arch. 1997 Dec;431(6):391-406
references.pmid: 9428927