This 400-page book provides an introduction to bioinformatics and describes how it can be used as a powerful tool to retrieve and analyze vast amounts of biological data from a wide range of species. The fourth edition has been revised and updated with two new chapters and increased coverage of metabolic pathways and gene expression/regulation. Written primarily for biological audiences without programming expertise, the book guides readers on how to use various bioinformatics methods and includes examples, exercises, and an online resource center to encourage self-directed learning.