The invention discloses nearly 474 novel phosphorylation sites identified in signal transduction proteins and pathways underlying human carcinoma, and provides phosphorylation-site specific antibodies and heavy-isotope labeled peptides (AQUA peptides) for the selective detection and quantification of these phosphorylated sites/proteins, as well as methods of using the reagents for such purpose. Among the phosphorylation sites identified are sites occurring in the following protein types: Kinase, Adaptor/Scaffold proteins, Phosphatase, G protein Regulator/Guanine Nucleotide Exchange Factors/GTPase Activating Proteins, Cytoskeleton Proteins, DNA Binding Proteins, Phospholipase, Receptor Proteins, Enzymes, DNA Repair/Replication Proteins, Adhesion Proteins, and Proteases, as well as other protein types.