Gene co-expression network construction. Gene co-expression networks built from sets of differentially expressed genes. For each time point, 4 co-expression networks were built using the differentially expressed (DE) genes and the samples from that time and dose comparison. For instance, at time 0 h, the co-expression networkA was built from the expression of the 810 DE genes in the samples exposed to 10 cGy and non-exposed samples (Dose 0 cGy). Similarly, the co-expression networkB was constructed using the 525 DE genes from samples exposed to 100 cGy and non-exposed samples. Co-expression networks netAB1 and netAB2 were built using the set of DE genes common to both dose0-10 and dose0-100 comparisons but with different samples.