Much of the recent spectacular progress in the biological sciences can be at tributed ot the ability to isolate, analyze, and structurally characterize proteins and peptides which are present in cells and cellular organelles in only very small amounts. Recent advances in protein chemistry and in particular the application of new micromethods have led to fruitful advances in the understanding of basic cellular processes. Areas where protein-chemical studies have resulted in interest ing discoveries include the peptide hormones and their release factors, growth factors and oncogenes,...