Contents of Part C. Introduction. Early development of nucleoside markers for cancer (T.P. Waalkes, C.W. Gehrke). 1. Progress and future prospects of modified nucleosides as biological markers of cancer (R.W. Zumwalt et al.). 2. Ribonucleosides in biological fluids by a high-resolution quantitative RPLC-UV method (K.C. Kuo et al.). 3. Ribonucleosides in body fluids: On-line chromatographic cleanup and analysis by a column switching technique (E. Schlimme, K. Siegfried-Boos). 4. High-performance liquid chromatography of free nucleotides, nucleosides, and their bases in biological samples (P.R. Brown, Y.-N. Kim). 5. Isolation and characterization of modified nucleosides from human urines (G.B. Chheda et al.). 6. High performance liquid chromatography of modified nucleosides in human serum (E.P. Mitchell et al.). 7. Modified nucleosides in human blood serum as biochemical signals for neoplasia (F. Salvatore et al.). 8. Biochemical correlations between pseudouridine excretion and neoplasias (F. Cimino et al.). 9. High-performance liquid chromatography analysis of nucleosides and bases in mucosa tissues and urine of gastrointestinal cancer patients (K. Nakano). 10. Modified nucleosides as biochemical markers of asbestos exposure and AIDS (O.K. Sharma, A. Fischbein). 11. RNA catabolites in health and disease (I. Clark et al.). 12. Serum nucleoside chromatography for classification of lung cancer and controls (J.E. McEntire et al.). 13. Modified nucleosides and nucleobases in urine and serum as selective markers for the whole-body turnover of tRNA, rRNA, and mRNA-cap - Future prospects and impact (G. Schöch et al.). Combined Subject Index for Parts A, B and C.