The Protein Information Resource: an integrated public resource of functional annotation of proteins. - Cathy H. Wu; Hongzhan Huang; Leslie Arminski; Jorge Castro-Alvear; Yongxing Chen; Zhang-Zhi Hu; Robert S. Ledley; Kali C. Lewis; Hans-Werner Mewes; Bruce C. Orcutt; Baris E. Suzek; Akira Tsugita; et al. (Nucleic Acids Res., 2002)