Differentially expressed phosphoproteins (DEPPs) were classified based on the PANTHER (Protein ANalysis THrough Evolutionary Relationships) system (http://www.pantherdb.org), which is a unique resource that classifies genes and proteins by their functions [49] . The DEPP interaction network was build automatically by the STRING (Search Tool for the Retrieval of Interacting Genes/Proteins) system with default setting except that organism, confidence(score), and additional (white) nodes were set to ''human'', ''0.20'', and ''10'', respectively [50, 51] . The gene name list of these proteins was input to search against the database which contains known and predicted protein-protein interactions. The retrieve included a detailed network which highlights several hub proteins. The identified phosphoproteins were compared to the public database of PhosphoSite (http://www.phosphosite.org/) to find out the novel phosphoproteins and phosphosites. Each confirmed phosphoprotein was searched with SCANSITE (http:// scansite.mit.edu) [52] for potential kinase motifs with high, medium, and low stringency.