Experiments were performed in accordance with the National PI3K inhibitor Experimentation Manual. RNA samples from four irradiated mice and one shamirradiated mouse were used to detect gene expression changes at each time point. Gene expression profiling was performed using Illunima��s MouseWG-6 Beadchips . The biotinylated and amplified cRNA was generated from the total RNA samples using the Illumina TotalPrep RNA Amplification Kit . All the procedures were based on the manufacturer��s RNA amplification protocol, consisting of reverse transcription to synthesize first strand cDNA with a T7 Oligo Primer. The cDNA then underwent second strand synthesis and purification, followed by in vitro transcription with T7 RNA Polymerase to generate multiple copies of biotinylated cRNA. After sample labeling, five labeled and amplified cRNAs samples were hybridized to Illumina Mouse-6 Expression Bead Chips, following the manufacturer��s protocols. Images were extracted using the Illumina Iscan Reader and the final text file was output through Illumina��s Genome Studio application after data normalization based on average normalization algorithms. The normalized signal intensity of significant differential genes was used to build a coexpression network. At first, the Pearson��s correlation of each pair of genes was calculated as the basis of choosing the significant correlation gene pairs. Then the gene-gene interaction network was established according to the correlation between genes. Within the network analysis, nodes represent the genes, and the edges between genes depict the interaction between them . All the nodes were marked with degree, which is defined as the link numbers one node has to the other. Genes with higher degrees occupied more central positions in the network and had a stronger capacity of modulating adjacent genes. In addition, k-core in graph theory was applied to describe the characteristics of the network including, but not limited to, the centrality of genes within a network and the complexity of the subnetworks. According to the relationship between genes, they were divided into several subnetworks, and marked with different colors .