During the past year researches on the biochemistry of cancer have con tinued at an increasJng pace, which places the reviewer at a correspondingly increased disadvantage. In treading a tortuous path between the opposing goals of all-inclusiveness and critical evaluation, the reviewer finds himself entangled in a maze of almost inexhaustive literature (over 1200 references were considered), which taxes to the utmost his resources of judgment and common sense. A brilliant precedent has been set by Haddow (1), whose re view on the same subject in last year's volume shows an impressive grasp of the fields of oncology, biology, physics, and chemistry and which is writ ten in a characteristically lucid and elegant style.Because of the stringent limitations of space, it has been necessary to curtail subject matter strictly to studies concerned directly with cancer. The following topics, many with enough material to justify separate re views, have been arbitrarily excluded: effects of tumors on serum and urinary enzyme levels, diagnostic tests, clinical evaluation, the mechanisms of radiation effects, histochemistry, morphology, chemical syntheses and isola tions, genetics, biology of transplantation, steroid metabolism, oncolytic viruses, plant and reptilian tumors, and cytogenetics. Lest the reader feel that this review is all-exclusive it should now be mentioned that carcino genesis, tumor biochemistry and immunology, and chemotherapy will be dealt with in that order.An attempt has been made to cover the literature through September, 1955, and there has been little duplication of references cited by Haddow (1). CARCINOGENESISDuring the past year there has been an increased acceptance of the concept of protein deletion as playing a key role in the initiation of chemical carcinogenesis. The pioneer demonstration by the Millers in 1947 (2) that, following feeding of DAB, bound dye was found in the liver proteins, was followed by the development of an impressive correlation between protein binding and the carcinogenic process (3). Miller demonstrated (4) that fol lowing application of BP to the skin of mice, fluorescence was liberated by 1 The following abbreviations are used in this chapter: AAF for 2-acetylamino fluorene; ACTH for adrenocorticotrophic hormone; ADP for adenosinediphosphate; ATP for adenosinetriphosphate; BA for l,2-benzanthracene; BP for benzpyrene; DAB for p-dimethylaminoazobenzene; DBA for dibenzanthracene; DMBA for 9,10dimethyl-l,2-benzanthracene; DNA for deoxyribonucleic acid; DPN for diphos phopyridine nucleotide ; DPNH for diphosphopyridine nucleotide (reduced form) ; MeA for methyIcholanthrene; RNA for ribonucleic acid; TEM for triethvlene melamine.Annu. Rev. Biochem. 1956.25:573-612. Downloaded from www.annualreviews.org Access provided by University of Western Ontario on 02/07/15. For personal use only. Quick links to online content Further ANNUAL REVIEWS Annu. Rev. Biochem. 1956.25:573-612. Downloaded from www.annualreviews.org Access provided by University of Western Ontario on 02/07/15. For ...