The articles in the present volume are by major contributors to our under standing of signaling pathways affecting protein synthesis. They focus pri marily on two extracellular anabolic signals, although others are included as well. Insulin is one of the best-studied extracellular regulators of protein syn thesis. Several of the known pathways for regulation of protein synthesis were elucidated using insulin-dependent systems. Regulation of protein synthesis by amino acids, by contrast, is an emerging field that has recently received a great deal of attention. The dual role of amino acids as...