Abstract
Inferring a protein's function by homology is a powerful tool for biologists. The Princeton Protein Orthology Database (P-POD) offers a simple way to visualize and analyze the relationships between homologous proteins in order to infer function. P-POD contains computationally generated analysis distinguishing orthologs from paralogs combined with curated published information on functional complementation and on human diseases. P-POD also features an applet, Notung, for users to explore and modify phylogenetic trees and generate their own ortholog/paralogs calls. This unit describes how to search P-POD for precomputed data, how to find and use the associated curated information from the literature, and how to use Notung to analyze and refine the results.